We got a call from a restaurant group in Soho last year. Three sites, roughly forty pieces of HVAC and refrigeration equipment between them, and not a single maintenance record on file. Their previous contractor had been “servicing” the systems twice a year — turning up, swapping a filter, and leaving an invoice. No pressure checks. No coil cleans. No electrical testing. Just a filter swap and a signature.

Within the first month of taking over their PPM contract, we found a refrigerant leak on a walk-in cold room that had been losing charge for at least six months, two split systems running with completely blocked condensers, and a cellar cooler with a failed condensate pump that had been dripping into the ceiling void. Total cost of the remedial work was under £3,000. The cost of ignoring it for another six months would have been five times that — plus the stock losses, plus the EHO inspection risk, plus the ceiling repair.

That’s the difference between PPM that’s done properly and PPM that’s just a line item on someone’s compliance checklist.

What PPM Actually Means at ADK

PPM stands for Planned Preventative Maintenance. The “planned” part matters. Before we touch a single unit, we survey the site, document every piece of equipment — make, model, serial number, refrigerant type and charge, location, age, condition — and build a maintenance schedule tailored to that specific site. A busy restaurant kitchen in Covent Garden needs quarterly visits at minimum. An office with four wall-mounted splits might only need biannual servicing. A cold storage facility running 24/7 needs monthly checks on critical systems.

From Daikin, Mitsubishi Electric, and Foster to specialist systems, ADK engineers have hands-on experience with the equipment our London clients rely on every day.

The schedule isn’t arbitrary. It’s based on manufacturer recommendations, the operating environment, regulatory requirements (particularly F-Gas leak check frequencies), and our own experience of what fails and when. After maintaining commercial HVAC and refrigeration across London since 2009, we’ve got a fairly clear picture of which components wear out, which environmental conditions accelerate degradation, and which corners people cut that come back to bite them.

What We Check on Every PPM Visit

Air Conditioning Systems

• Filter inspection and replacement — clogged filters reduce airflow, increase compressor load, and degrade indoor air quality. In London, filters in restaurant environments can block in as little as 8 weeks
• Evaporator and condenser coil cleaning — the condenser coil is the number one cause of AC breakdown we see. Grease, dust, pollen, and urban grime accumulate faster than most people realise
• Refrigerant pressure and superheat/subcooling checks — a system low on charge runs inefficiently and will eventually damage the compressor. We measure actual operating pressures against manufacturer specs, not just check the gauges are “in the green”
• Electrical connections, contactors, and capacitors — loose terminals cause intermittent faults. Worn contactors cause noisy operation and eventually fail to close. Run capacitors degrade with age and cause compressor startup problems
• Condensate drain clearance and pump testing — blocked drains cause water leaks. In ceiling-mounted cassettes, that means water dripping onto desks, stock, or diners
• Thermostat and controller calibration — a controller reading 2°C too high means the system runs longer than it needs to. A controller reading 2°C too low means the space never reaches comfort temperature and you get complaints
• Airflow measurement and fan speed verification — reduced airflow means reduced capacity. We measure actual airflow against commissioning data where available
• Compressor operating current and voltage — elevated current draw is an early warning of bearing wear or winding degradation. We catch failing compressors weeks before they actually stop

Commercial Refrigeration Systems

• Temperature logging and verification — we check actual product temperatures, not just the controller display. A fridge can display 3°C on the panel while the product at the back is sitting at 7°C if airflow is restricted
• Door seals and gasket inspection — worn seals on walk-in doors and reach-in cabinets are the silent killer of efficiency. The compressor runs overtime compensating for warm air ingress, energy bills climb, and eventually the system can’t cope
• Defrost cycle verification — on cold rooms and freezers, incorrect defrost settings cause ice buildup on evaporator coils. Too little defrost and the coils block. Too much defrost and you get temperature spikes that compromise food safety
• Condenser cleaning — same story as AC. In commercial kitchens, condenser coils on undercounter and reach-in fridges accumulate grease and flour dust at an alarming rate. We see units failing within 3 years purely because nobody ever cleaned the condenser
• Refrigerant charge and leak checks — mandatory under F-Gas regulations for systems above certain charge thresholds, and essential for reliable operation regardless of the legal requirement
• Compressor oil level and condition — on semi-hermetic compressors (Bitzer, Copeland), oil condition tells us a lot about the health of the refrigeration circuit

F-Gas Compliance — It’s Not Optional

Under the UK F-Gas regulations, any system containing fluorinated greenhouse gases must have regular leak checks. The frequency depends on the CO2-equivalent charge of the refrigerant:

• 5-50 tonnes CO2eq: annual leak check
• 50-500 tonnes CO2eq: leak check every 6 months (or annually with a permanent leak detection system)
• 500+ tonnes CO2eq: leak check every 3 months (or every 6 months with leak detection)

The fines for non-compliance are significant, but the real risk is an undetected leak slowly degrading your system’s performance until it fails completely. We include F-Gas leak checks as standard on every PPM visit and maintain the required records — serial numbers, refrigerant quantities, leak check results, and any top-ups or recoveries — in a format that satisfies auditors and inspectors.

We provide planned preventative maintenance services across the capital, including Central London, South London, and every borough in between. Fast response times are built into our service model.

The Financial Case for PPM

We track maintenance data across our entire contract base. The numbers consistently show that businesses on PPM contracts spend 40-60% less on total HVAC and refrigeration costs over a three-year period compared to businesses that only call when something breaks. The reasons aren’t complicated:

• Emergency callouts cost 2-3x more than scheduled visits — out-of-hours labour rates, expedited parts sourcing, and the urgency premium all add up
• Clean systems use less electricity — a condenser running with 30% airflow restriction uses measurably more power. Across a site with 10+ units, the energy savings from regular coil cleaning alone often cover the cost of the PPM contract
• Equipment lasts longer — a well-maintained Daikin VRV system should run 15-20 years. A neglected one might last 8-10 before the compressor gives up
• Fewer stock losses — for refrigeration clients, one prevented cold room failure easily saves more than a year’s worth of PPM fees
• Budget predictability — a fixed annual maintenance cost is easier to budget for than random repair bills of unpredictable size

What a PPM Contract Includes

Every ADK maintenance contract is tailored to the site, but all contracts include:

• Scheduled service visits at agreed intervals (monthly, quarterly, biannual, or annual)
• Full written report after every visit with findings, photos, and any recommended remedial work
• F-Gas compliance documentation maintained and available on request
• Priority emergency response — contract clients go to the front of the queue
• Fixed pricing — no surprises on the invoice
• Direct access to our service desk for fault reporting and scheduling
• Annual equipment condition report with lifecycle recommendations

We maintain systems from all major manufacturers: Daikin, Mitsubishi Electric, Fujitsu, Samsung, Panasonic, LG, Carrier, Toshiba on the AC side. Foster, Williams, Hoshizaki, True, Polar, Gram on the refrigeration side. Bitzer, Copeland, Danfoss, Emerson on the component side.

Common faults we encounter during planned preventative maintenance work include condensing units tripping on high pressure and AC systems short-cycling. Both are significantly cheaper to prevent than to repair after a full failure.

Who Uses Our PPM Service

Our PPM client base includes restaurants, hotels, pubs, schools, offices, retail stores, healthcare facilities, data centres, commercial landlords, and facilities management companies across London. Some have a single split system. Others have 100+ units across multiple sites. The approach scales — we have multi-site clients where we coordinate access with building managers, security teams, and tenant schedules across a dozen locations.

Every engineer who visits your site is directly employed by ADK, F-Gas certified, DBS checked, and trained on the specific equipment they’re servicing. We don’t subcontract maintenance work. Ever.

Get a PPM Quote

If you’re spending money on reactive repairs and wondering if there’s a better way, there is. Call us on 020 3974 1419 or fill in the contact form and we’ll arrange a free site survey. We’ll assess every unit, build a maintenance schedule, and give you a fixed annual price. No obligation.