It’s 7pm on a Friday in July. The bar’s three-deep and your Hoshizaki IM-240 has stopped dropping ice. The bin’s half empty. You’ve got maybe an hour before you’re serving warm gin and tonics and the bar manager is losing his mind.
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.
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.
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.