Thermistor
Common temperature-sensing fault part. Confirm resistance range and connector.
True Refrigeration E2 Error Code — What It Means
The E2 error on True Refrigeration equipment signals a high temperature alarm — the cabinet temperature has exceeded the high-temp threshold set in the controller (typically 50°F on refrigerators, higher on freezers). True’s controllers monitor cabinet temperature continuously; if it rises above the alarm setpoint for a sustained period, E2 triggers to alert you that product may be at risk.
Common Causes
- Door left open or door gasket failure — The most common cause. Warm ambient air enters freely and overwhelms the refrigeration system.
- Dirty condenser coil — True units, especially undercounters and reach-ins in food service environments, accumulate grease and dust on the condenser rapidly. A choked condenser can’t shed heat and cabinet temps rise.
- Refrigeration system fault — Low refrigerant, failed compressor, or a stuck TXV will reduce cooling capacity and allow cabinet temp to climb.
- Defrost system not completing — If defrost heaters or the defrost thermostat fail, frost accumulates on the evaporator, restricting airflow and reducing cooling.
Step-by-Step Fix
- Check the door and gasket — Open and close each door. Verify the gasket seals fully around the perimeter. A torn or stiff gasket lets warm air in continuously. Replace if damaged.
- Clean the condenser coil — Pull the unit away from the wall. The condenser is typically at the bottom front behind a grille on True reach-ins. Vacuum or brush the coil and fan blades. Grease-laden condensers in kitchens may need a degreaser.
- Check condenser fan operation — Confirm the condenser fan is spinning when the compressor is running. A failed condenser fan motor will cause rapid cabinet temp rise.
- Inspect the evaporator for frost — If the evaporator (inside the refrigerated space, behind the back panel) is heavily frosted, the defrost system has failed. Check heater resistance and defrost thermostat continuity.
- Reset the alarm — After correcting the root cause, the E2 alarm on most True controllers clears automatically once cabinet temp returns below the alarm threshold. Power cycle if it doesn’t clear.
Parts Often Needed
| Part | Notes |
|---|---|
| Door gasket | Match to model; True has model-specific gaskets |
| Condenser fan motor | Replace if not spinning with compressor on |
| Defrost heater / thermostat | If evaporator is frosted over |
Technician Tips
When diagnosing commercial refrigeration faults, start with the controller’s alarm history. Most digital controllers (Dixell, Carel, Eliwell) store the last 5-10 alarms with timestamps. An E1 alarm that appears consistently every few hours suggests a sensor going bad — the resistance value drifts until it’s out of range. An intermittent HI/LO alarm that appears only during hot afternoons suggests a condenser issue, not a sensor fault.
Prevention: Schedule quarterly condenser coil cleaning. Dirty coils are the #1 cause of high-head-pressure faults and compressor overheating in commercial refrigeration. Use a soft brush and compressed air — never a pressure washer on the coil fins.
Need Replacement Parts?
Before ordering, match the refrigeration part to the model number, electrical rating, and failure symptom. Check current prices on Amazon - prices and availability change frequently.
When to Call a Pro
If the condenser is clean, doors seal well, and the defrost system is intact but the cabinet still can’t hold temp, the sealed refrigeration system (compressor, TXV, refrigerant) needs a certified tech.