Step 1: Confirm the reading
A high display reading isn't always a failure. Check whether the door has just been opened, a delivery has just been loaded or a defrost cycle is running. Probe a product in the warmest part of the cabinet, or a simulant bottle. Check the thermometer itself if the reading seems implausible. If the air is warm but product is within limit, close the door and re-check after 20 to 30 minutes.
Step 2: Assess the food
Two questions decide what happens to food: how warm did it get, and for how long? A data logger or min/max thermometer answers the second question; without one, assume the worst time since the last good reading.
Your food-safety plan should set the decisions in advance. The table shows the kind of logic many plans use; your own limits take priority.
| Situation | Typical action |
|---|---|
| Product at or below 5 °C; air briefly high | Keep; fix cause; re-check |
| Product above 5 °C for a short time within your plan's limit | Move to a working unit; use soon; record |
| Product above 5 °C for longer than your plan allows, or unknown time | Discard high-risk food; record what and why |
| Frozen food still frozen hard with ice crystals | Keep frozen or move to another freezer; quality may suffer |
| Frozen food fully thawed and warm | Decide under your plan; often discard high-risk items |
Step 3: Protect the rest of the stock
- Move high-risk and ready-to-eat food to a unit that is working.
- If no space is available, use insulated boxes with ice or gel packs for short periods.
- Keep the faulty unit's door shut while you investigate, to hold whatever cold remains.
- Don't load any more food into the faulty unit.
Step 4: Find the cause
| Possible cause | What to check |
|---|---|
| Door not closing | Door left ajar, items blocking it, torn or hardened gasket |
| Overloading or warm food | Large hot pots, blocked air vents, food against the fan |
| Dirty condenser | Dust or grease on the coil; poor airflow around the unit |
| Ice build-up | Heavy frost on the evaporator; failed defrost |
| Fan failure | Evaporator or condenser fan not running |
| Power and voltage | Tripped breaker, loose plug, low voltage, recent outage |
| Settings | Controller setpoint changed by mistake |
Step 5: Call for service when needed
If simple checks don't explain the fault, or the unit cannot get back to temperature with the door shut, call a qualified refrigeration technician. Don't attempt repairs on the sealed refrigeration system, electrical components or flammable-refrigerant units yourself. Tell the technician what you saw: readings, times, noises, ice, and anything that changed recently.
Step 6: Record and review
Write it down: the reading, the time, what food was affected, what was kept or discarded and why, the cause, who decided and when the unit was back in range. These records show inspectors that the system works, and they reveal patterns. A unit that runs warm every afternoon is telling you it is under-sized for its job or sited in the wrong place.
Frequently asked questions
- Can I just turn the thermostat colder when a fridge reads warm?
- Sometimes the setpoint has drifted or been changed, and correcting it is right. But turning it colder doesn't fix a torn gasket, a dirty condenser or a failing fan, and it can freeze food near the evaporator. Find the cause first.
- Who should decide whether food is discarded?
- A trained person named in your food-safety plan, usually the shift supervisor or Food Safety Supervisor, following the plan's limits. Decisions should not be left to whoever happens to notice the reading, and they should always be recorded.
