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Cellar cooling is one of those systems that works quietly in the background until it doesn’t — and then it becomes the most expensive problem in the building. Wasted beer, unhappy punters, and a phone call to the brewery that nobody wants to make.

Faults like this are common across commercial sites in Brixton. Enrolling in a PPM schedule helps catch the warning signs early, reducing the chance you will ever need an refrigeration installation.

Why Temperature Matters This Much

Different products need different temperatures, and getting it wrong affects every pint you pull:

• Cask ale: 11–13°C. Too cold and the flavour flattens out. Too warm and it conditions too fast, goes lively, and starts fobbing at the tap.
• Keg lager and cider: 3–5°C. Needs to be properly cold for a clean, tight pour.
• Stout on nitro: 6–8°C. Slightly warmer than lager to get the right creamy texture.

Most pub cellars target a compromise around 11–12°C, with the python (the insulated bundle of lines running from cellar to bar) providing additional chilling for products that need serving colder.

Temperature swings are just as bad as a consistently wrong temperature. A cellar that bounces between 8°C at night and 16°C during a busy Saturday creates havoc with cask conditioning and causes excessive fobbing at every tap.

The Symptoms

You don’t always need to check the thermometer to know something’s off:

Foamy pints. Excessive fobbing is usually the first indicator. Warm beer releases dissolved CO₂ faster when it hits the glass, creating more foam than the pour should produce. If your fob-to-pour ratio suddenly jumps, check the cellar before you blame the line clean.

Flat cask beer. Cask ale that’s gone flat or lost its condition has been too warm for too long. The secondary fermentation that gives cask its character speeds up with heat, and the cask blows through its natural carbonation faster than it should.

High wastage. If your weekly wastage numbers are creeping up and nothing else has changed — same cleaning schedule, same gas pressure, same pour technique — the cellar temperature is the next thing to check.

Warm kegs to the touch. Walk into the cellar and put your hand on a keg. If it doesn’t feel distinctly cold, the room’s not doing its job.

What Goes Wrong

Condenser Problems

The cellar cooler works like any refrigeration system: it absorbs heat from the cellar air and rejects it somewhere else, usually via a remote condenser on the roof or an outside wall. If the condenser is blocked with dust, leaves, moss, or bird debris, it can’t reject heat efficiently. Head pressure rises, cooling capacity drops, and the cellar temperature starts climbing.

Roof-mounted condensers in London take a beating from the weather and the wildlife. We’ve pulled pigeon nests out of condensers, scraped moss off coil fins, and cleared years of accumulated grime from units that hadn’t been serviced since installation.

The fix is condenser cleaning — and making sure it happens regularly, not just when the cellar overheats.

Refrigerant Leak

If the cellar cooler has gradually lost performance over weeks or months — maintaining 12°C last winter, struggling at 14°C in spring, hitting 18°C now — the refrigerant charge is almost certainly dropping. Slow leaks on cellar coolers often happen at pipe joints, especially where the indoor unit connects to the remote condenser via copper pipework running through the building.

Under F-Gas regulations, the leak has to be found and fixed before we recharge. We carry leak detection equipment on every van.

Thermostat and Controller Faults

The cellar cooler’s thermostat tells the system when to run and when to stop. If it fails or reads incorrectly, the system either runs non-stop (driving the cellar too cold, icing up cask ale and causing its own fobbing problems) or doesn’t run enough (letting the temperature drift up).

Some pub cellar coolers use simple mechanical thermostats that drift with age. Others use digital controllers that can lose their calibration or develop sensor faults. Either way, if the controller’s not reading the actual room temperature accurately, the system can’t maintain the right conditions.

Insufficient Capacity

This one’s not a fault — it’s a design problem. The cellar cooler was sized for the cellar as it was originally configured, and things have changed since then. More stock stored in the cellar generating thermal mass. A bigger glass washer installed that throws heat. The cellar door left open more often because it’s being used as a thoroughfare.

We have written a separate guide on cellar coolers freezing up which covers a related failure mode worth checking. Similarly, our article on glycol chillers not cooling enough explains another common cause of the same underlying issue.

In some cases, the pub itself has expanded — more taps, more kegs, more throughput — and the cellar cooling system was never upgraded to match. The unit runs flat out and still can’t hold temperature on a warm Saturday afternoon.

Poor Insulation

A cellar with poor insulation is a cellar that gains heat from every direction. Warm air from the pub above coming through an uninsulated ceiling. Heat from a boiler or hot water pipes running through the cellar. Sunlight hitting an exposed external wall.

Some pub cellars are naturally cool — stone-built basements that barely shift in temperature year-round. Others are converted ground-floor rooms with single-brick walls and no insulation. The cooling system has to overcome whatever heat gains the building allows in, and in a poorly insulated space, that can be a losing battle.

Maintenance Keeps It Running

A cellar cooler that’s serviced twice a year — condenser cleaned, refrigerant pressures checked, thermostat calibrated, electrical connections tested — will run reliably for years. The ones that get forgotten about until July, when the cellar hits 20°C and the wastage goes through the roof, are the expensive ones.

We also check the cellar environment during a service visit: door seals, insulation condition, heat sources that shouldn’t be there, airflow around the evaporator. The cooler is only half the equation — the cellar itself needs to give the system a fighting chance.

Cellar Cooling Down? Call Us

If your cellar’s warming up and the pints are suffering, call us on 020 3974 1419. We install, maintain, and repair cellar cooling systems across London’s pubs, bars, restaurants, and hotels. F-Gas certified, fast response, and we understand that when the cellar goes down, every hour matters.

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The post Beer Cellar Cooling Problems — What’s Going Wrong and How to Fix It first appeared on ADK Kooling.

We’ve had this exact call more times than we can count. Ice machines are the equipment nobody thinks about until they stop — and then they become the most urgent problem in the building.

We handle this type of problem frequently for businesses in Central London and the surrounding area. If your system is showing these symptoms, our PPM team can usually diagnose the root cause on the first visit.

The Quick Checks

Before you call anyone, run through these. We attend callouts for all of them regularly, and if you can rule them out, it saves everyone time.

Water supply. Ice machines need a constant water feed. The inlet tap is usually on the wall behind or beside the machine, and it gets knocked closed in tight bar areas where staff are squeezing past thirty times a service. Check it’s fully open. Also check the supply line for kinks — a pinched pipe restricts flow enough to stop production.

Water filter. If you’ve got an inline water filter on the supply (you should — it protects the machine and improves ice quality), check whether it’s blocked. Filters have a limited life, typically six months depending on London’s water quality. A blocked filter starves the machine of water. You might see it going through its cycle but producing thin, undersized, or misshapen cubes before it gives up entirely.

Ambient temperature. Ice machines are more sensitive to room temperature than people realise. Most are rated to operate up to 35–40°C, but performance drops significantly in hot environments. If your machine is in an unventilated back room, next to the glasswasher, or in a plant room that catches heat from the kitchen, it’s fighting an uphill battle.

The condenser needs to reject heat to the surrounding air. If that air is already at 38°C, the machine’s efficiency falls off a cliff. We’ve relocated ice machines from hot plant rooms to cooler positions and seen output double overnight.

When It’s a Real Fault

Condenser Blockage

Same story as every other refrigeration unit: if the condenser coils are blocked with dust, grease, or lint, the machine can’t reject heat and the refrigeration cycle breaks down. On Hoshizaki machines, the condenser is usually at the back or bottom. On Scotsman units, it varies by model.

In a bar or restaurant environment, the condenser picks up everything — flour from the kitchen, lint from bar towels, general dust. A machine that was making perfect ice six months ago can gradually decline to nothing purely because nobody’s cleaned the condenser.

Scale Build-Up

London has hard water. Calcium and limescale deposits build up on the evaporator plate (where the ice actually forms) and inside the water distribution system. Heavily scaled evaporator plates produce thinner, cloudier ice in lower quantities — and eventually the scale builds up enough to prevent ice forming at all.

Most commercial ice machines have a cleaning/descaling cycle that should be run regularly. Hoshizaki recommend it every six months; Scotsman and Manitowoc have similar schedules. If your machine hasn’t been descaled in a year or more, that’s likely contributing to reduced output.

Harvest Failure

Ice machines work in cycles: freeze, harvest, freeze, harvest. During the harvest cycle, the machine releases the formed ice from the evaporator plate (usually by running warm refrigerant through it or spraying warm water) so the cubes drop into the storage bin. If the harvest cycle fails, ice stays stuck to the evaporator and the next freeze cycle builds on top of it. You end up with a thick slab of ice on the evaporator and an empty bin.

Harvest failures can be caused by a faulty hot gas valve, a stuck water valve, a thermostat that isn’t reading correctly, or a mechanical issue with the harvest mechanism. This is engineer territory — but the clue is visible if you open the machine up and see a solid block of ice on the evaporator instead of individual cubes or bullets.

Refrigerant Issues

If the machine is cycling normally but the evaporator plate isn’t getting cold enough, the refrigerant charge may be low. This is less common on self-contained ice machines (the refrigerant circuit is sealed at the factory) but it does happen, particularly on older machines where vibration has worked on a joint over the years.

If your site uses Hoshizaki units, our specialist engineers know these systems inside out. This problem often goes hand in hand with commercial fridge not cooling, so it is worth investigating both if you are experiencing intermittent faults.

The Maintenance Angle

An ice machine that’s properly maintained — condenser cleaned, filters changed, descaled on schedule, water filter replaced — runs reliably for years. The Hoshizaki machines we maintain in some of London’s busiest cocktail bars have been running for a decade with nothing more than routine servicing.

Neglect it and you’re looking at breakdowns at the worst possible time. Always during a heatwave. Always on a Friday night.

Most ice machine manufacturers recommend professional servicing every six months. That covers condenser cleaning, descaling, sanitisation of the water circuit and storage bin, electrical checks, and a general performance assessment. Twice a year, and the machine just works.

Get It Fixed

If your ice machine has stopped producing and the quick checks haven’t solved it, call us on 020 3974 1419. We work with all major brands — Hoshizaki, Scotsman, Manitowoc, Brema, Ice-O-Matic — and we know these machines inside out. Most faults diagnosed on the first visit.

Commercial refrigeration services →

The post Ice Machine Not Making Ice — What to Check first appeared on ADK Kooling.

This isn’t unusual. Overheating kitchens are one of the most common problems in London’s restaurant scene, and the root cause is almost always the same: the ventilation was either designed wrong, installed wrong, or never designed at all.

Our engineers see this fault regularly across Shoreditch. A PPM contract catches this kind of issue early, well before it escalates into a costly commercial AC installation.

What the Regulations Actually Say

Commercial kitchen ventilation isn’t optional — it’s a legal requirement. Building Regulations Part F covers ventilation in non-domestic buildings, and the industry standard that matters is DW/172 — the BESA specification for kitchen ventilation systems.

DW/172 sets out the design requirements: canopy types, extraction rates, make-up air volumes, grease filtration stages. If your kitchen ventilation wasn’t designed to this spec, there’s a good chance it’s not extracting enough air for the heat load your equipment is throwing out.

Gas safety adds another layer. If you’ve got gas cooking equipment, the ventilation system needs to supply enough air for combustion as well as heat removal. An extraction system that’s too powerful without adequate make-up air creates negative pressure in the kitchen — and that can interfere with gas appliance flues. Dangerous territory.

Why Your Kitchen Is Too Hot

Not Enough Extraction

Most common issue we see. The kitchen canopy is either too small for the cooking line, or the extraction rate (measured in litres per second or m³/hour) is too low for the heat output of the equipment underneath it.

This happens a lot when kitchens evolve. A restaurant opens with a small menu and modest equipment. Three years later they’ve added a charcoal grill, a tandoor oven, and two extra fryers. The cooking capacity has doubled but the extraction system is exactly the same. The canopy that was adequate for the original fit-out is now hopelessly undersized.

The only fix is matching the extraction to the heat load. That might mean a larger canopy, higher-capacity fans, or additional extraction points over the new equipment. We carry out heat load calculations to DW/172 and design the extraction around what’s actually in the kitchen, not what was there five years ago.

No Make-Up Air

This is the one most people don’t think about. Every cubic metre of air you extract from a kitchen has to be replaced by fresh air from somewhere. If there’s no dedicated make-up air system, that replacement air gets pulled in through doors, windows, gaps under walls — wherever it can find a way in.

The problems: uncontrolled draughts that mess with cooking equipment, doors that are hard to open because of negative pressure, and in winter, a blast of freezing air hitting the chef every time someone opens the kitchen door. Some kitchens get so negative that the extraction system itself can’t work efficiently because there’s not enough incoming air to push against.

A proper make-up air unit — tempered in winter so it’s not blowing 2°C air into a 35°C kitchen — transforms the working environment. Air goes in at a controlled rate, gets heated up by the kitchen equipment, and gets extracted by the canopy. The kitchen stops fighting against itself.

Grease Filters Blocked

The baffle filters in your extraction canopy trap grease before it enters the ductwork. When they’re clean, they let air pass through while capturing grease particles. When they’re caked in weeks of accumulated cooking fat, they restrict airflow like a pillow over the vent.

Grease filters should be cleaned weekly at minimum — more often in high-volume kitchens. They’re designed to be removable and dishwasher-safe. If your kitchen staff aren’t cleaning them regularly, extraction performance drops, the kitchen gets hotter, and grease starts migrating into the ductwork where it becomes a fire risk.

Spot Cooling Needed

Even with perfect extraction, some areas of a commercial kitchen will always be hot. The pass (where plated food sits under heat lamps), the area around the charcoal grill, and the dishwash section all generate intense localised heat. Extraction deals with the overall kitchen air, but these hotspots need targeted cooling.

We install spot cooling units — small, focused AC units designed for commercial kitchen environments. They’re not trying to air-condition the whole kitchen (which is a losing battle when the grill’s on); they’re putting a stream of cooled air exactly where the chef is standing. The difference for staff comfort and productivity is immediate.

If you are also experiencing kitchen extraction not pulling properly, the two faults may share a common cause. Our engineers frequently find that addressing one resolves the other. You might also want to read our guide on dishwasher areas running too hot and humid for additional troubleshooting steps.

Duct Cleaning and Fire Safety

While we’re on the topic: when was your kitchen ductwork last cleaned? Grease accumulation in extract ducts is one of the leading causes of kitchen fires. The insurance companies know this — many policies require annual duct cleaning with a certificate of compliance.

TR/19, the BESA guide to ductwork hygiene, sets out the cleaning standards. A proper duct clean includes access panels, visual inspection, internal cleaning, and photographic evidence of the before and after state. If your kitchen extraction hasn’t been cleaned internally since it was installed, it needs doing.

The Full Picture

A commercial kitchen ventilation system isn’t just a canopy and a fan. It’s extraction matched to heat load, make-up air to replace what’s extracted, grease filtration to protect the ductwork, and potentially spot cooling for the worst hotspots. All of it designed as one system, not cobbled together piece by piece.

We design, install, and maintain kitchen ventilation systems across London’s restaurants, hotels, pubs, and commercial catering operations. We understand DW/172 requirements and can assess whether your current setup is actually doing its job — or just making noise.

Call us on 020 3974 1419 to arrange a kitchen ventilation assessment. Or if it’s already 45°C in there and you need help now, we can do that too.

Ventilation services →

The post Commercial Kitchen Too Hot — Ventilation That Actually Works first appeared on ADK Kooling.

But when that background noise changes — gets louder, takes on a new character, starts happening at intervals — pay attention. A commercial freezer that’s developing a new sound is usually telling you something is about to fail. The type of noise is often the best clue to what’s going wrong.

This is one of the most common callouts we attend across North London. If your system has not been serviced recently, booking a emergency breakdown service visit can often resolve the underlying cause before a full breakdown occurs.

Buzzing or Humming — Louder Than Normal

Every compressor hums when it’s running. That’s the electric motor doing its job. But if the hum is noticeably louder, or the compressor is vibrating more than it used to, the motor’s struggling.

This usually means internal components are wearing, the start relay is on its way out, or the compressor is working against abnormally high head pressure. High head pressure typically comes from a dirty condenser — grease and dust restricting airflow so the system can’t reject heat properly. On a Foster or Williams blast freezer in a busy kitchen, the condenser can go from clean to completely blocked in a matter of months.

A buzzing sound where the compressor doesn’t actually start is more serious. The motor’s trying to turn over but can’t. Failed start relay, dead capacitor, or worst case — the compressor is mechanically seized. You’ll often feel the housing running hot even though it’s not pumping. That one needs an engineer.

Clicking — The Repetitive Cycle

Repetitive clicking, every few minutes, is one of the classic signs of a compressor in trouble. Here’s what’s happening: the compressor tries to start, draws a high inrush current, and the thermal overload trips to prevent the motor burning out. The compressor stops, cools for a few minutes, tries again. Click, hum, click, silence. Repeat.

This cycle can go on for hours — even days — before the compressor gives up entirely. Each failed start stresses the motor windings and the electrical contacts. The earlier you get an engineer to it, the more likely it is that a start component replacement saves the compressor. Leave it clicking all weekend and you might be looking at a full compressor swap on Monday morning.

Rattling or Vibrating

A rattle usually points to something mechanical that’s come loose or worn. Fan blade hitting its guard. Compressor mounting bolts loosened by vibration. Panels or covers that have worked free. A condenser fan motor with a worn bearing will rattle before it seizes — that’s your warning window.

On reach-in freezers, check the bottom panel and the condenser fan area. On chest freezers and island display units, the compressor compartment is usually at one end. Anything that was tight when the unit was installed can loosen over years of vibration.

Gurgling or Bubbling

Some gurgling is normal — that’s refrigerant moving through the system. But if the gurgling is louder or more constant than usual, or if it’s accompanied by reduced freezing performance, the refrigerant charge might be low. As gas leaks out, the remaining refrigerant can create more audible turbulence through the expansion valve and evaporator.

On larger systems with Bitzer or Copeland semi-hermetic compressors, a gurgling or slugging sound from the compressor itself can indicate liquid refrigerant reaching the compressor — a condition called liquid slugging that can cause valve damage. That one needs attention quickly.

High-Pitched Whining

A high-pitched whine from the compressor area often means the bearings are going. Compressor bearings don’t give you much warning — they go from whining to seizing in a timeframe that could be days or could be hours. If you hear a new high-pitched sound from a commercial freezer, get it looked at sooner rather than later.

Fan motor bearings make a similar sound but are much cheaper and quicker to replace. An engineer can usually tell the difference on site by isolating the fan circuit and listening to the compressor on its own.

We have written a separate guide on a cold room compressor running constantly which covers a related failure mode worth checking. Similarly, our article on walk-in freezers not holding temperature explains another common cause of the same underlying issue.

What to Do

Don’t ignore new noises. A failing start relay on a commercial freezer is a £150 repair. A seized compressor is £800–£2,000+ depending on the unit, plus the cost of any stock you lose while it’s being replaced.

Note what the noise sounds like, when it happens (constant, intermittent, or cyclical), and whether the freezer is still holding temperature. That information helps us turn up with the right parts.

If the freezer is still working but noisier than usual, it can usually wait until the next working day for a service call. If it’s clicking repeatedly and the temperature is climbing — that’s an emergency. Stock at risk.

Call us on 020 3974 1419 for commercial freezer diagnosis and repair across London. We work on all makes — Foster, Williams, Hoshizaki, True, Polar, Gram — and carry common parts including start relays, capacitors, fan motors, and thermostats on the vans.

Commercial refrigeration repair →

The post Commercial Freezer Making Loud Noise — What It Means first appeared on ADK Kooling.

Here’s the shortcut. We’ve listed the error codes we see most often on the three brands that dominate London’s commercial buildings — Daikin, Mitsubishi Electric, and Fujitsu. This isn’t every code (each manufacturer has hundreds), but it covers the faults that generate the majority of our callouts.

We see this issue regularly in West London. A proactive emergency breakdown service agreement is the best way to prevent this fault from recurring, and it means faster response times if you do need an commercial AC installation.

Before You Read the Codes: The Pattern Matters

If you manage a building with multiple indoor units — ceiling cassettes across an office floor, wall units in a restaurant, ducted systems in a hotel — the pattern of errors tells you more than the code itself.

One unit showing an error, rest working fine. The fault’s on that specific indoor unit. Fan motor, expansion valve, thermistor, drain issue. Lower urgency unless it’s above the server rack or the CEO’s office.

Multiple units showing the same error at the same time. The fault’s almost certainly on the outdoor unit or the shared refrigerant circuit. This is the urgent one — it usually means an entire floor or zone has lost cooling.

Different errors on different units. Could be a communication bus fault rippling through the system, or a power issue causing cascading trips. Note down all the codes and report the lot.

Knowing this distinction before you call us saves time and helps us send the right engineer with the right parts.

Common Daikin Error Codes

We’re a Daikin D1 partner, so we see these daily across London’s offices and restaurants.

E1 — PCB Fault. Internal fault on the circuit board. Worth trying a power cycle first — switch it off at the isolator (not the remote), wait 30 seconds, switch back on. Some transient faults clear themselves. If E1 comes back, the board likely needs replacing. On a VRV system, an E1 on one indoor unit won’t affect the rest.

E7 — Fan Motor. The indoor fan has failed or isn’t responding. The unit won’t run because it can’t circulate air. In a building with 20 cassettes, one dead fan motor is an inconvenience, not an emergency — unless it’s above the boardroom during a client meeting.

U0 — Low Refrigerant. The system’s detected low pressure, which almost always means a leak. Do not keep resetting the unit. Running a system with low gas damages the compressor, and compressor replacement costs ten times what a leak repair costs. On VRV systems, a U0 on the outdoor unit will affect every indoor unit connected to it.

U4 — Communication Error. Indoor and outdoor units aren’t talking to each other. Damaged signal cable, loose connection, or a PCB fault. On VRV systems where the communication bus is daisy-chained through multiple indoor units, a single break can take out every unit downstream. We had a case in a Shoreditch office where a data cabling contractor had cut through the Daikin comms wire while running CAT6. Took out AC to the whole floor.

A3 — Condensate Drain Issue. The float switch has detected that water isn’t draining away. The unit shuts down to stop water pouring through the ceiling — which is better than the alternative, but still leaves a zone without cooling. This is the most preventable fault on the list: a routine drain flush during a PPM visit stops it happening entirely.

Common Mitsubishi Electric Error Codes

E6 — Indoor/Outdoor Communication Error. Same story as Daikin’s U4 — the units have lost communication. On City Multi VRF systems, this can cascade across multiple indoor units if the main bus is disrupted.

E9 — Serial Communication Fault. The wired wall controller can’t talk to the indoor unit. Usually a wiring problem — damaged cable, reversed polarity, or water ingress into the controller’s terminal block. We see this a lot after office refurbishments where ceiling work has disturbed the cabling.

P8 — Pipe Temperature Sensor. A thermistor (small temperature sensor clipped to the refrigerant pipe) is reading out of range or has failed. Without it, the system can’t regulate itself properly. Quick fix — clip on a new one. No need to touch the refrigerant circuit.

Common Fujitsu Error Codes

Fujitsu units — especially the older ones — tend to use LED flash patterns rather than alphanumeric codes. Newer Airstage models show codes on the wired controller.

Operation and Timer LEDs flashing together. Both the green (operation) and orange (timer) LEDs flashing simultaneously usually means an outdoor unit fault. The specific flash count tells us which fault, but from your end, the message is: this isn’t going to clear itself with a reset.

This problem often goes hand in hand with a multi-split indoor unit not working. If you are noticing both symptoms, it is worth getting an engineer out before the system fails completely. We have also covered Daikin U4 communication faults in a separate guide.

E1:00 or EE:EE. Significant system fault — communication failure between indoor and outdoor, or a major component failure on the outdoor unit. The system won’t run until an engineer’s diagnosed and repaired it.

What to Do When You See a Code

Try a power cycle. Isolator off, 30 seconds, back on. Not the remote — the actual isolator switch. Voltage spikes and transient sensor glitches can throw a code that clears on restart.

If the code comes back:

1. Photograph the display. The exact code, including any sub-codes. This saves us 15 minutes of on-site diagnosis.
2. Walk the floor. Check every unit you can see. How many are affected? This one piece of information tells us more than anything else about whether it’s a local or system-wide fault.
3. Check the outdoor unit if you can access it. Fan running? Compressor humming? Error code on the outdoor display panel?
4. Don’t keep resetting it. If the same code keeps coming back, the system’s trying to protect itself. Overriding that protection — or repeatedly cycling the power — can turn a £300 repair into a £3,000 one.

Most of These Are Preventable

This is the part nobody wants to hear, but it’s true: most of the error codes we clear on emergency callouts could have been caught during a routine service visit.

• A3 condensate faults — prevented by drain flushing every visit
• E7 fan motor faults — early signs (bearing noise, high current draw) are detectable during inspection
• U0 low refrigerant — pressure checks catch slow leaks months before the system trips
• Icing and airflow faults — regular filter cleaning prevents the restriction that causes them

A structured maintenance programme across all units in a building catches these systematically, rather than waiting for a code to appear and a zone to go offline.

Need an Engineer?

If your AC system’s showing an error code and you need it diagnosed, call us on 020 3974 1419. We work on Daikin, Mitsubishi, Fujitsu, Samsung, and all other commercial split and VRF systems across London. Daikin D1 partner with direct access to their technical support line and parts supply.

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The post Split System Error Codes Explained — Daikin, Mitsubishi & Fujitsu first appeared on ADK Kooling.

The fix took 20 minutes. Blocked condensate drain, cleared with a wet vac and treated with biocide. But the water damage to two ceiling tiles, a keyboard, and the dignity of a senior partner — that was the expensive part.

Faults like this are common across commercial sites in Central London. Enrolling in a PPM schedule helps catch the warning signs early, reducing the chance you will ever need an commercial AC installation.

AC water leaks are one of the most common calls we get across London’s offices, restaurants, and retail spaces. Almost all of them are preventable.

Why AC Units Produce Water

Quick explanation for anyone who hasn’t thought about this before: when an AC unit cools the air, it also pulls moisture out of it. Warm humid air passes over the cold evaporator coil, the moisture condenses (exactly like a cold beer glass on a summer day), and the water collects in a drain tray underneath. From there, it flows down a drain line to a waste pipe — by gravity if you’re lucky, or via a small condensate pump if the drain point is above the unit.

On a muggy London day in August, a single ceiling cassette can produce several litres of condensate. In a restaurant kitchen where humidity is already through the roof from cooking, it’s even more. All normal. The problem starts when that water doesn’t go where it’s supposed to.

What Goes Wrong

Blocked Drain Line

Number one cause by a distance. The condensate drain is a narrow-bore pipe running from the unit to a waste point. Over months, algae, mould, dust, and general slime build up inside it. The flow slows, then stops. The drain tray fills up, and water spills over the edge — usually straight through the ceiling.

In offices with ceiling cassettes, the first sign is stained ceiling tiles. Then sagging tiles. Then dripping. And if the unit happens to be above a row of desks with monitors and docking stations, you’ve got a facilities manager fielding angry emails by lunchtime.

In restaurants, it’s worse. A leaking AC unit above a food prep area is a food hygiene issue. An EHO inspector will flag it. It’s not a good look.

The fix is simple: flush the drain line, treat it with condensate tablets or biocide to slow regrowth. It’s a standard check on every PPM visit we do. The fact that we see this fault so often tells you how many buildings aren’t on a proper maintenance schedule.

Condensate Pump Failure

Not every unit can drain by gravity. Basement offices, rooms where the nearest drain point is higher than the unit, installations where the pipework route makes gravity drainage impractical — these all need a condensate pump.

These pumps are small, reliable, and forgotten about until they fail. The pump motor burns out, the float switch sticks, or the reservoir gets clogged with the same biological sludge that blocks drain lines. When the pump dies, the water has nowhere to go.

Most commercial installations have a safety float switch that kills the AC unit before the tray overflows. Good for preventing water damage, bad for the building occupants who suddenly lose cooling in the middle of summer. You get a choice: water damage or overheating.

Frozen Evaporator Coil

This one catches people out. The symptom is a water leak, but the actual cause is ice. If the evaporator coil gets too cold — usually because a dirty filter has restricted airflow, or the refrigerant charge is low — ice forms on the coil during operation. When the unit cycles off or conditions change, that ice melts all at once. The drain tray wasn’t designed for that volume of water in one hit, and it overflows.

If someone reports ice or heavy frost on the coil or pipes, turn the system off and let it defrost. Check the filter — if it’s choked, that’s probably your answer. If the filter’s clean and it still ices up, the system likely has a refrigerant leak. That needs an F-Gas engineer with gauges and a leak detector.

Cracked Drain Tray

Less common but worth knowing about on older units — 10+ years in service. The tray can crack, corrode (metal trays in humid environments), or shift so it’s no longer level. A tilted tray pools water at one end and overflows before it reaches the drain outlet.

What It Actually Costs When AC Leaks in a Commercial Building

The repair itself is usually cheap — a drain flush, a pump replacement, a filter change. But the collateral damage is where the bill lands:

If you are also experiencing AC short cycling causes and fixes, the two faults may share a common cause. Our engineers frequently find that addressing one resolves the other. You might also want to read our guide on split system error codes for additional troubleshooting steps.

• Ceiling tiles — stained or waterlogged tiles in a client-facing office or meeting room need replacing. Not expensive per tile, but the disruption and appearance matter.
• IT equipment — water on laptops, monitors, servers, network switches. A single soaked network switch in a comms room can bring down connectivity for an entire floor.
• Tenant complaints — in managed buildings, a persistent water leak from the landlord’s AC system is the kind of issue that escalates to formal letters and rent reduction negotiations.
• EHO risk — in restaurants and food environments, water dripping anywhere near food handling areas is a compliance problem.
• Business disruption — desks relocated, meeting rooms out of action, restaurant sections closed while it’s being sorted.

All preventable with twice-yearly maintenance.

How to Stop It Happening

Every one of the faults above gets checked during a proper AC service visit:

• Drain line flushed and treated
• Condensate pump tested and cleaned
• Filters cleaned or replaced
• Drain tray inspected for cracks and correct alignment
• Refrigerant pressures checked to prevent coil icing

We recommend servicing commercial AC at least twice a year — pre-summer and pre-winter. For buildings with a lot of ceiling cassettes in dust-heavy environments (restaurants, retail, older offices), quarterly makes more sense.

A planned maintenance contract covers all of the above and gives you priority response if something does go wrong between visits. Cheaper than one emergency callout with ceiling damage.

Got a Leaking AC Unit?

Don’t leave it. Water damage gets worse, not better, and a dripping unit above expensive equipment or a food area isn’t something to ignore. Call us on 020 3974 1419 and we’ll get it sorted.

AC repair service → | Maintenance contracts →

The post Air Conditioning Unit Leaking Water — Causes and Fixes first appeared on ADK Kooling.

It sounds like a small thing. It isn’t. A cold room with a failed door seal runs its compressor significantly harder just to maintain temperature. Energy bills creep up. The evaporator ices over because warm, humid air is constantly infiltrating the room. And eventually, especially during a summer heatwave when the kitchen’s pushing 35°C, the system can’t keep up and your stock is at risk.

We handle this type of problem frequently for businesses in South London and the surrounding area. If your system is showing these symptoms, our PPM team can usually diagnose the root cause on the first visit.

We probably replace or repair ten cold room door seals a month across London. It’s one of the most common — and most overlooked — maintenance issues in commercial kitchens.

How to Tell the Seal Has Failed

The door gasket’s job is simple: create an airtight barrier between the warm kitchen and the cold room interior. When it fails, the signs are consistent:

Ice around the door frame. This is the big one. Warm, moist kitchen air enters through the gaps, hits the cold surfaces inside the door frame, and freezes. If you’re seeing frost or ice build-up on the inside of the frame — especially along the hinge side or the bottom — the seal is leaking.

Compressor running constantly. A healthy cold room cycles on and off as the thermostat calls for cooling. If yours is running non-stop, it’s working overtime to compensate for the heat infiltration. Apart from driving up your electricity bill, continuous running puts stress on the compressor and shortens its life.

Temperature swings. Instead of holding a steady 2°C, you see the room swing between 1°C and 6°C as the system fights against the warm air ingress. Your HACCP records might show more temperature excursions than normal. That’s the kind of pattern an EHO inspector will pick up on.

The door doesn’t “suck” when you pull it open. A well-sealed cold room creates a slight vacuum effect — you feel a small amount of resistance when opening the door. If it opens freely with no resistance, there’s no seal.

Why Seals Fail

Wear and tear. In a busy kitchen, the cold room door might open and close a hundred times a day. Kitchen porters pushing trolleys through, chefs grabbing ingredients mid-service, delivery drivers loading stock in. The gasket takes physical punishment — it gets knocked, stretched, compressed, and gradually loses its shape and magnetic grip.

Thermal cycling. The gasket lives at the boundary between a 2°C cold room and a 30°C kitchen. That constant temperature differential causes the rubber to harden and crack over time. Cheaper gaskets deteriorate faster, but even good quality ones have a finite lifespan.

Physical damage. Trolley wheels rolling over the bottom gasket. Tray edges catching the side seal. Door hinges wearing so the door hangs slightly off-square, putting uneven pressure on the gasket. We’ve seen cold room doors that close fine at the top but have a 5mm gap at the bottom — enough to pour warm air through.

Hinge and closer problems. The door itself might be fine, but if the self-closing mechanism is weak or the hinges have worn, the door doesn’t shut fully. It looks closed, but there’s no compression on the gasket. Staff don’t notice because they’re in a rush. The system compensates for hours until it can’t.

Fixing It

Gasket Replacement

Most cold room doors use a push-in or clip-on magnetic gasket that sits in a channel around the door frame. Replacing it is straightforward if you can source the right profile — and that’s the catch. Cold room manufacturers use different gasket profiles, and the wrong shape won’t seat properly.

We carry the most common profiles on the vans and can source specialist gaskets within 24–48 hours for less common door types. On panel-built cold rooms from the likes of Foster, Williams, or Dagard, the gaskets are usually standard. On bespoke builds, it sometimes takes a bit of detective work.

Door Realignment

If the door is sagging on its hinges, replacing the gasket alone won’t solve the problem. The door needs to close square in the frame for the gasket to compress evenly all the way around. This might mean adjusting the hinges, replacing worn pivot pins, or shimming the frame. On heavy insulated doors — the kind you see on large walk-in cold rooms — the hinges take significant weight and the pivot points wear over time.

We have written a separate guide on walk-in fridge temperatures running too high which covers a related failure mode worth checking. Similarly, our article on cold room evaporator icing up explains another common cause of the same underlying issue.

Self-Closer Adjustment

The door closer (usually a hydraulic or spring-loaded arm) ensures the door shuts fully after someone walks through. If it’s lost tension or the arm is bent, the door creeps to almost-closed but doesn’t compress the gasket. Adjusting or replacing the closer is a quick fix with a big impact.

Strip Curtains

Not a fix for a bad seal, but a smart addition. PVC strip curtains inside the cold room doorway dramatically reduce warm air infiltration during the periods when the door is physically open. In high-traffic kitchens, they’re one of the most cost-effective things you can do — they pay for themselves in reduced energy costs within a few months.

The PPM Angle

Door seal checks should be part of every planned maintenance visit. It takes two minutes to do the paper test on every seal, check the hinge tension, and verify the closer is working. Catching a deteriorating gasket early means a scheduled replacement at a convenient time — not an emergency callout when the cold room’s at 10°C and you’ve got a full house booked.

On our PPM contracts, door seal inspection is standard on every visit. It’s one of those small checks that prevents expensive problems.

Need a Cold Room Door Repair in London?

If your cold room door isn’t sealing and the temperature’s climbing, call us on 020 3974 1419. We carry common gasket profiles and can usually get it sorted on the first visit. For unusual profiles, we’ll measure up, source the right part, and come back within 48 hours.

Cold room services →

The post Cold Room Door Not Sealing — How to Fix It first appeared on ADK Kooling.

We get this call two or three times a week across London, and the first 30 minutes matter more than people realise. Everything from here is about how fast you act.

Our engineers see this fault regularly across East London. A emergency breakdown service contract catches this kind of issue early, well before it escalates into a costly refrigeration installation.

Why 30 Minutes Matters

Food stored above 8°C enters the danger zone for bacterial growth. Your EHO inspector doesn’t care why the temperature went up — they care that it did and what you did about it. If you can get the fault identified and the cold room pulling back down to temp quickly, you might save the stock. Leave it four hours and you’re looking at a full write-off and an uncomfortable conversation with your food safety auditor.

Log the temperature immediately. Check your HACCP records. If the stock has been above 8°C for an extended period, it needs assessing — and in many cases, binning. It’s painful, but it’s less painful than a food poisoning incident and the rating drop that follows.

What’s Causing It

Condenser Coils Clogged

We’d put money on this being the fault before we even walk through the door. The condenser — whether it’s on the roof, on a wall bracket outside, or in a plant room — rejects heat from the system. In a kitchen environment, grease vapour, flour dust, and general airborne gunk coat those coils fast.

When the condenser can’t breathe, the whole system struggles. Head pressure rises, the compressor runs flat out, and the cold room can’t maintain its set point. We’ve attended sites where the remote condenser hadn’t been cleaned in two years. Completely furred up. The compressor was running at 110% and the cold room was sitting at 12°C on a mild day. On a hot day, it would have tripped out entirely.

Condenser cleaning is a ten-minute job during a routine service visit. When it’s left until the system fails, it becomes an emergency callout.

Low Refrigerant

If the cold room has been gradually losing performance over days or weeks — holding 4°C last month, 6°C last week, 9°C this morning — the charge is almost certainly leaking out somewhere. The system’s designed to operate with a specific weight of refrigerant. As it drops, cooling capacity drops with it.

Common leak points on walk-in systems: brazed joints on the pipework, Schrader valve cores, the compressor shaft seal on semi-hermetic units, and anywhere vibration has been working on a pipe for years. Under F-Gas regs, we locate and repair the leak before recharging. No exceptions.

Evaporator Icing Up

Open the cold room door and look at the evaporator coil (the unit with the fans mounted high up on the wall). If it’s covered in a thick layer of ice, there’s your problem. The ice insulates the coil and blocks airflow, so even though the system’s running, it can’t transfer heat out of the room.

Icing happens for a few reasons: the defrost timer has failed or is set wrong, the defrost heaters have burned out, or the system’s low on gas (which drops the evaporator temperature below the icing threshold). Some operators try to speed things up with hot water or a heat gun — don’t. You’ll damage the coil fins. Switch off the system, open the doors, and let it defrost naturally. Then call us to fix the underlying cause.

Door Seal Failure

Walk-in cold room doors take a hammering. Kitchen porters going in and out with trays, trolleys banging the frame, years of thermal cycling causing the gasket to harden and crack. Once the seal is compromised, warm, humid kitchen air leaks in constantly.

The telltale sign is ice build-up around the inside of the door frame. That’s moisture from the warm air freezing on contact with the cold surfaces. The compressor runs harder to compensate, energy bills climb, and eventually the system just can’t keep up.

Check the seal by closing the door on a piece of paper. If you can pull the paper out easily, the seal isn’t doing its job.

Fan Motor Failure

Walk-ins typically have two or three evaporator fans. If one fails, you might not notice immediately — the cold room still works, just less effectively. Temperature becomes uneven: cold near the working fans, warmer in the far corners. Product near the back of the room starts reading higher than the controller display would suggest.

This problem often goes hand in hand with cold room door sealing issues. If you are noticing both symptoms, it is worth getting an engineer out before the system fails completely. We have also covered commercial fridge not cooling in a separate guide.

This is why we tell clients not to rely solely on the controller reading. That sensor is in one position. The temperature three metres away could be completely different when a fan’s down.

Overloading

This one’s not a fault — it’s operational. If you’ve just taken a large delivery and loaded 200kg of ambient-temperature product into the cold room at once, the system has to work much harder to pull all that thermal mass down to temp. On a hot day, a fully loaded walk-in might take hours to recover.

Best practice: stage your deliveries. Don’t load everything in at once. And if possible, pre-cool product in a separate area before transferring it to the walk-in.

What You Can Check Before We Arrive

• Controller display — what temperature is it reading? Any error codes or alarm indicators?
• Evaporator coil — iced up, or clear with fans running?
• Door seal — any visible damage, ice around the frame, light coming through gaps?
• Condenser (if accessible) — can you see daylight through the coil, or is it blocked?
• Has anything changed recently? New equipment nearby generating heat? Door propped open during a busy service?

Keep the Door Shut

It sounds obvious but it’s worth saying: every time the door opens, warm air rushes in. While you’re waiting for the engineer, keep the door closed as much as possible. If the system is still running (just not holding temp), keeping the door shut gives it the best chance of at least limiting the damage.

Don’t Wait for It to Get Worse

A walk-in that’s struggling at 8°C today will be at 15°C tomorrow if the underlying fault isn’t fixed. And that’s when you start losing stock.

Call us on 020 3974 1419 for same-day cold room repair across London. We work on all makes — Foster, Williams, Hoshizaki, Hubbard, Dawsongroup, bespoke panel builds — and we carry refrigerant, common parts, and leak detection equipment on every van.

The post Walk-In Fridge Temperature Too High — Causes and What to Do first appeared on ADK Kooling.

The thing is, when a single wall-mounted split stops cooling, it’s usually a simple fix. But when you’re managing an office building with a Daikin VRV system running 30 ceiling cassettes off two outdoor units, or a restaurant with a ducted Mitsubishi City Multi setup — and the whole thing stops pulling its weight — the diagnosis is different, the stakes are higher, and you need someone who actually understands commercial systems.

This is one of the most common callouts we attend across Canary Wharf. If your system has not been serviced recently, booking a commercial AC installation visit can often resolve the underlying cause before a full breakdown occurs.

First Question: One Zone or the Whole Building?

This is the most important thing you can figure out before calling us. It tells the engineer whether they’re looking at a single indoor unit fault or a system-level problem that affects the entire refrigerant circuit.

One Zone Down, Everything Else Fine

If one ceiling cassette is blowing warm while the rest of the floor is cold, the fault is almost certainly on that individual indoor unit. The usual suspects:

Blocked filters. Ceiling cassettes in commercial spaces swallow dust. In restaurants near the kitchen extraction, it’s worse — cooking grease gets pulled into the return air and coats the filter media. A clogged filter chokes the airflow across the evaporator coil, and the unit can’t cool even though the refrigerant circuit is working fine. We’ve pulled filters out of ceiling cassettes in City restaurants that looked like they’d been dipped in cooking oil. Change them quarterly at minimum.

Failed fan motor. The indoor fan pulls air across the evaporator coil. If it dies, the unit looks like it’s responding to commands from the controller, but nothing’s actually moving. On ceiling cassettes this is hard to spot because you can’t see the fan from below — you just notice the room getting warm.

Stuck expansion valve. On VRF systems, each indoor unit has its own electronic expansion valve (EEV) that meters refrigerant flow. If it sticks closed, that unit gets no refrigerant and can’t cool. The rest of the system carries on as normal. This is one of the most common single-zone faults on Daikin VRV and Mitsubishi City Multi. You won’t diagnose this one without a refrigeration engineer and a set of gauges.

Wiring or comms fault. VRF systems use a communication bus between indoor and outdoor units. A damaged cable, a dodgy PCB, or an addressing error on one unit can stop it from talking to the system. After office refurbishments — ceiling tiles moved, data cabling run, partitions shifted — we regularly find that someone’s nicked through a comms wire.

Whole Building or Multiple Zones Down

This is the urgent one. If several indoor units or the entire system is blowing warm, the fault is almost certainly on the outdoor unit or the shared refrigerant circuit.

Outdoor unit trip. The outdoor unit houses the compressor and condenser. If it’s tripped on a safety protection or locked out on an error code, every indoor unit connected to it loses cooling. On a VRF system serving an entire office floor, that’s 10, 20, sometimes 30+ units going warm simultaneously. Check if the outdoor unit’s fan is running — if it’s silent, that’s your answer.

Refrigerant leak. A gradual leak shows up as a system that copes on mild days but can’t keep up when it’s 30°C outside. Over weeks, performance degrades until the system trips on low-pressure protection. Under F-Gas regs, we have to find and fix the leak before recharging. No shortcuts.

Condenser blockage. The outdoor unit needs clear airflow to reject heat. Rooftop units are usually fine. Ground-level or balcony units in London? They get buried in leaves, litter, and whatever the wind blows in. We attended a Mayfair office last year where someone had stacked delivery boxes against the outdoor unit. Head pressure through the roof.

Inverter board failure. Modern commercial systems use inverter-driven compressors. If the inverter board goes, the compressor shuts down entirely. On VRF units with twin compressors, you’ll get reduced capacity rather than a total loss — every zone runs lukewarm instead of cold.

VRF Systems: A Different Animal

VRF (or VRV if it’s Daikin) dominates London’s commercial buildings. It’s the right technology for the job — efficient, flexible, simultaneous heating and cooling across different zones. But the complexity means you need a contractor who works on these systems daily, not someone who usually does domestic installs and had a go.

A VRF system might have 40 indoor units, a bank of outdoor units, electronic expansion valves on every head, oil management systems across long pipe runs, and a communication network tying it all together. When something goes wrong, the outdoor unit displays an error code — but reading that code and tracing the actual root cause requires VRF-specific training and diagnostic software.

We’re a Daikin D1 partner, which means direct access to Daikin’s technical support line, their diagnostic software, and their parts supply chain. We also work on Mitsubishi City Multi, Fujitsu Airstage, Samsung DVM, and Carrier systems across London’s commercial stock every week.

Ceiling Cassettes and Ducted Systems

Ceiling cassettes are the workhorse of commercial AC in offices and retail. Recessed into the suspended ceiling, four-way air distribution, out of sight. When one stops cooling, it’s usually filters, condensate drain (more on that below), or the fan motor.

If you are also experiencing AC thermostats reading the wrong temperature, the two faults may share a common cause. Our engineers frequently find that addressing one resolves the other. You might also want to read our guide on AC short cycling causes and fixes for additional troubleshooting steps.

One thing people miss with ducted systems: the unit itself might be working perfectly, but the ductwork is the problem. Damaged or disconnected ducts behind the ceiling, closed fire dampers that nobody reopened after testing, or insulation that’s degraded so the cooled air warms up before it reaches the room. An engineer who only checks the mechanical unit and ignores the distribution side will miss this.

What to Tell Us When You Call

This genuinely saves time and often means a first-visit fix:

• How many zones are affected — one cassette, one floor, or the whole building?
• Is air coming out of the vents? Warm air = refrigerant or compressor issue. No air = fan or power issue.
• Any error codes on the wall controllers? Take a photo. Saves 15 minutes of diagnosis.
• Is the outdoor unit running? Fan spinning? Compressor humming?
• Sudden or gradual? Dead this morning = component failure. Getting worse all week = leak or blockage.
• Any recent building work? Electrical changes, ceiling work, BMS updates — all can affect the AC.

Maintenance Stops This Happening

We say this every time because it’s true every time: the majority of these callouts are preventable. Dirty filters, blocked condensers, low refrigerant, failing fan bearings — all detectable during a routine service visit, all fixable before they take a zone offline.

On multi-unit VRF systems, maintenance is even more critical because one undetected fault — a slow leak, a failing EEV — can cascade into a system-wide problem that costs five times more to fix.

AC Down? Give Us a Call

If your building’s overheating and the AC isn’t playing ball, call us on 020 3974 1419. We work on VRF, multi-split, ducted, and cassette systems across offices, restaurants, hotels, retail, and server rooms all over London.

AC repair and breakdown service →

The post AC System Not Cooling Your Building — What’s Going Wrong first appeared on ADK Kooling.