Walk-in Cooler Warm
A restaurant walk-in runs but will not hold temperature and product is warming. Read the box, then airflow, then the condenser — sealed system last.
Scenario briefing
The call
A restaurant reports their walk-in cooler is running but not holding temperature. Product on the shelves is beginning to warm and the kitchen manager is watching you.
The unit appears to be operating — you hear fan and compressor activity — but the box is not getting cold enough. There is no alarm and no error code on the control.
Work the sequence: confirm the real box temperature, then airflow at the evaporator, then heat rejection at the condenser. Sealed-system work is the last stop, not the first.
The condensing unit runs, the evaporator fans push box air across a cold coil, and the box holds setpoint with periodic defrosts that clear the frost the coil naturally builds. Product is protected by air movement as much as by refrigeration — a walk-in with a cold coil and no airflow will still warm up.
Subsystems in this failure pattern
- Air side: evaporator coil, evaporator fans, box loading and door discipline
- Defrost: termination, timer or controller, drain line and heaters
- Refrigeration and load: condensing unit, condenser coil, door gaskets and infiltration
Why this diagnostic order
Product is at risk, so you take a real temperature and protect the load first. Airflow and defrost faults cause the majority of warm-box calls and are visible without gauges. Refrigerant work comes last because a coil blanketed in ice will mislead every reading you take.
Step 0 · Required
Safety Gate
Confirm every item below before the diagnostic area unlocks. This mirrors the pre-work checklist you owe every customer.
0 of 5 confirmed.
Step 1 · First checks
LockedDiagnostic decision
You are at the box with the manager waiting. What do you do first?
Complete the safety gate to continue.
Component map
Walk-in cooler system — component view
System layout — relative positions
Progress
Step 1 of 4
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- 4