Thermistor
Common temperature-sensing fault part. Confirm resistance range and connector.
Error Codes: Traulsen G20010 Reach-In Freezer
What it means: The Traulsen G20010 is a premium two-section reach-in freezer used in restaurants, hospitals, schools, and institutional kitchens. It uses an electronic controller to watch cabinet temperature, evaporator temperature, and defrost performance. When a sensor fails or the freezer cannot hold temperature, the controller logs an error code or alarm.
Because the G20010 stores high-value frozen inventory, an error code on this unit creates immediate buyer intent. Owners need to know whether they can swap a sensor, replace a gasket, or call for sealed-system service before they lose product.
Traulsen G20010 Fault Code Reference
E1 — Cabinet Sensor Fault
The controller is not receiving a valid signal from the cabinet temperature sensor.
What it means: The thermistor that measures freezer air temperature has gone open, shorted, or drifted far enough out of range that the controller rejects it.
Common causes:
- Failed cabinet thermistor
- Wire damage inside the evaporator housing or controller compartment
- Condensation or corrosion in the connector
- Controller input issue, less common than the sensor itself
See also: Traulsen Refrigerator Error Code E1
E2 — Evaporator Sensor Fault
The evaporator coil sensor is not reading correctly.
What it means: The controller cannot judge coil temperature accurately, so defrost timing and fan protection become unreliable.
Common causes:
- Failed evaporator probe
- Sensor knocked loose from the coil
- Harness rubbed through on sheet metal
- Heavy ice damage near the probe location
E3 — Defrost Termination or Auxiliary Sensor Fault
On many Traulsen controllers, E3 indicates a defrost sensor or auxiliary sensor problem.
What it means: The freezer did not complete defrost in the expected way, or the board lost the sensor input needed to end defrost.
Common causes:
- Defrost sensor failed open or shorted
- Defrost heater not warming the coil
- Relay or board issue in the defrost circuit
- Evaporator packed with ice from a leaking gasket or fan issue
HI — High Temperature Alarm
The cabinet stayed above the acceptable freezer range for too long.
Common causes:
- Dirty condenser coil
- Door left ajar or bad magnetic gasket
- Evaporator fan not moving enough air
- Product loaded warm
- Low refrigerant charge
- Defrost problem creating poor airflow across an iced coil
PF — Power Failure or Temperature Recovery Alarm
Some Traulsen controllers show a power-failure style alarm after an outage or after cabinet temperature rises too high during a shutdown.
Common causes:
- Recent power outage
- Breaker trip
- Loose power connection
- Unit warmed during cleaning or after service and has not recovered yet
Common Causes on Traulsen G20010 Freezers
- Dirty condenser coils: Even premium Traulsen units lose capacity fast when the condenser gets packed with dust and grease. This is the first maintenance item to check.
- Door gasket leaks: A freezer pulls in moisture with every air leak. That moisture freezes on the evaporator and starts a chain of airflow and defrost problems.
- Sensor failure in a wet kitchen: Thermistors live in cold, damp environments. After years of cycling, they fail or drift out of spec.
- Evaporator icing from fan or defrost trouble: Once the coil ices up, the box warms and multiple alarms can follow even if the compressor still runs.
- Sealed-system loss on older units: A G20010 that runs long, struggles to pull down, and shows frost only on part of the evaporator may have a refrigerant leak or weak compressor.
Step-by-Step Fix {#step-by-step-fix}
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Record the alarm and the current box temperature. If product temperature is rising, move inventory to backup cold storage first.
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Clean the condenser coil. Remove the louver panel and clean the coil fully with a brush and vacuum. This simple step often resolves high temperature alarms on reach-ins.
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Check the door seal and door closure. Look for torn gaskets, sagging hinges, or product blocking the door from closing fully. A leaking freezer door creates frost fast.
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Test the cabinet and evaporator sensors. Disconnect each thermistor and measure resistance with a multimeter. Compare the reading to the expected sensor chart for your controller family. Replace any probe that reads open, shorted, or far off.
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Inspect the evaporator coil. If the coil is heavily iced, thaw it completely before you continue. Then confirm whether the icing came from a bad sensor, failed fan motor, leaking gasket, or defrost issue.
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Verify evaporator fan operation. Fans should spin freely and move strong air. A slow or dead fan can make the freezer look like a refrigerant problem when it is really an airflow problem.
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Check the defrost circuit if you have E3. Verify defrost heater continuity where applicable and confirm the board is initiating defrost properly. A failed heater or relay will keep the coil buried in ice.
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Compare displayed temperature to a real thermometer. If the display reads normal but product is soft, sensor drift or airflow problems are likely.
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Look for sealed-system warning signs. If the condenser is clean, sensors test good, fans run, and frost forms on only one small section of the evaporator, suspect low refrigerant or a restriction.
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Replace the controller only after confirming everything else. On G20010 freezers, bad probes, dirty condensers, and door leaks are all more common than a failed board.
Parts Often Needed {#parts-often-needed}
| Part | Notes | Typical Cost | Where to Buy |
|---|---|---|---|
| Cabinet temperature sensor | First check for E1 alarms | $20–$45 | Parts Town |
| Evaporator sensor | Common E2 or E3 repair | $20–$45 | Parts Town |
| Door gasket | Stops moisture entry and icing | $70–$140 | Parts Town |
| Evaporator fan motor | Needed when airflow drops | $75–$160 | Parts Town |
| Condenser fan motor | Helps with HI alarms and hot head pressure | $80–$170 | Parts Town |
| Defrost heater | Model-specific, verify voltage | $60–$140 | Parts Town |
| Electronic controller | Match the exact controller revision | $150–$300 | Parts Town |
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 Professional
Call a professional if the freezer still cannot hold temperature after you clean the condenser, confirm the fans work, and test the sensors. At that point the most likely problems are a refrigerant leak, a restricted metering device, a bad compressor, or a more complex control fault. Those repairs require commercial refrigeration tools and EPA 608 certification.
You should also call right away if the unit holds expensive proteins, ice cream, or medical product and the cabinet temperature is climbing. A G20010 full of inventory can rack up product loss faster than the service call costs.
Pro tip: A Traulsen freezer that runs all day and shows heavy frost only near the coil inlet usually has a sealed-system problem, not a sensor problem. That pattern matters more than the code by itself.
See Also
- Traulsen Refrigerator Error Code E1
- Traulsen RLT Error Codes
- Beverage-Air Refrigerator Error Code E1
- True Refrigeration Error Codes
- Turbo Air Freezer Error Code E2
- Commercial Refrigerator Error Codes