Before you call a refrigeration mechanic for a display fridge that's gone warm, walk through these five checks. Two of them are common DIY fixes, two of them are diagnostic, and the last one tells you whether you can keep going or whether it's time to pick up the phone. Across Central Coast cafes from Kincumber to Killcare, the same checks come up over and over.
1. Thermostat settings
Sounds obvious, but it's the first thing to rule out. Thermostats get bumped during stock rotation, knocked during cleaning, or accidentally adjusted by staff who didn't realise. Pull the thermostat dial back to the recommended setting (usually around 3-4°C for a chilled display) and watch what happens over the next hour.
2. Door seals — the paper test
Close a piece of A4 paper in the door so it's gripped between the seal and the frame. Try to slide it out. If it pulls out easily, the seal isn't making proper contact and the fridge is fighting a constant influx of warm air. Check around the whole door — top, bottom, both sides. A failed seal is a fixable thing on most commercial display fridges, often without replacing the door.
3. Condenser coils
Dust and grease build up on the condenser coils, usually located on the back or underneath the unit. The coil's job is to dump heat out of the system, and a dirty coil can't. Pull the unit forward, find the coil, and vacuum carefully — never push a vacuum nozzle hard against the fins, they bend easily and once bent, airflow is permanently reduced. If the build-up is greasy rather than dusty, a coil clean by a technician is the proper fix.
4. Airflow and stock loading
Display fridges rely on cold air circulating through the cabinet. Overload the shelves — pack everything tight, block the rear vents — and the air can't move. Cold air stays at the bottom, warm air pools at the top, and the thermostat reads the bottom while the top of the cabinet sits at 8°C.
Pull stock back from any visible vents, leave airflow channels around blocks of product, and re-check the temperatures over the next few hours.
5. Ice on the evaporator coils
Look for visible ice or frost building up on the evaporator (the coils inside the cabinet, usually behind a panel). A small amount during operation is normal — thick ice that doesn't clear during the defrost cycle is a sign that the defrost cycle isn't firing properly. This is a technician fix, but you can usually buy yourself time by switching the unit off for a few hours to let the ice clear before turning it back on.
When to stop and call
If those five checks haven't fixed it, the fault is most likely a compressor issue, a refrigerant leak, or a control board fault. None of these are safe DIY territory — refrigerants legally require an ARCtick licence to handle, and control boards are expensive to break.
Read more about commercial refrigeration repairs or check coverage on the Kincumber service area page.