FixGrid Academy — Field checklist
Walk-in Cooler Warm
Commercial walk-in cooler · Intermediate
Box temperature climbing with product at risk. Protect the product, then diagnose airflow before refrigerant.
1Safety first
- Open and lock out the disconnect before removing any panel.
- Confirm dead with a non-contact tester.
- Watch for standing water and ice on the floor under the evaporator.
- Gloves and eye protection; keep the door propped safely.
2First checks
- Take a real box temperature with your own thermometer.
- Confirm the door closes and gaskets seal; check for a stuck-open door.
- Verify the condensing unit is running and the evaporator fans are turning.
- Look for ice on the evaporator coil and in the drain pan.
3Narrow the system
- Split it: load/door issue vs airflow/defrost vs refrigeration side.
- Feel suction line temperature and check for frost back.
- Check the defrost termination and time clock/controller settings.
- Inspect the condenser coil for blockage and the fan for operation.
4Highest-probability tests
- Test each evaporator fan motor for run, amps, and free rotation.
- Verify the coil is clear — ice or debris blanketing the fins kills capacity.
- Check the drain line for a freeze-up backing water into the pan.
- Confirm defrost heaters/terminations behave through a manual defrost.
5Common outcomes and watch-outs
- Most common: iced, restricted coil driven by a failed evaporator fan motor.
- Fix the cause of the ice, not just the ice — you will be back otherwise.
- Move or protect product before the box warms further.
- Verify pull-down and log before/after temperatures for the manager.