Outdoor unit stops, indoor unit shows E3; system may start then quickly shut down.
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety first: Isolate power at the outdoor disconnect or breaker. Confirm the outdoor fan and compressor are not running before opening the panel.
Steps to try:
- Locate the sensor: Open the outdoor unit’s service panel. The condenser sensor is usually clipped to the condenser coil or attached to a refrigerant line.
- Check mounting: Ensure the sensor is firmly attached to the coil/pipe and not hanging loose. Re-clip or re-tie as needed for good thermal contact.
- Inspect wiring: Look for UV-damaged insulation, rodent bites, or pulled wires. Repair or replace damaged sections.
- Check connector: Verify the sensor plug is fully seated on the outdoor PCB and free of corrosion.
- Measure resistance: Disconnect the sensor and measure resistance at ambient temperature. Compare to Tristar’s spec. Replace the sensor if readings are open, shorted, or far out of range.
When to call a technician: If the sensor tests good but E3 persists, the outdoor PCB may need replacement and should be evaluated by a professional.
Repair Difficulty
Required Part
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