Tristar Defrost System Inefficiency

Unit runs in heating mode but outdoor unit becomes heavily iced over and heating performance drops.

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

Faulty outdoor coil temperature sensor, Defective defrost control on PCB, Outdoor fan not running at correct speed, Restricted outdoor airflow

Safety first: Turn off power before removing ice manually; do not use sharp tools on the coil.

Steps to try:

Clear snow and debris: Ensure the outdoor unit has free airflow and is not blocked by snow or plants.
Observe defrost cycles: In cold weather, the unit should periodically enter defrost. If it never does, a control issue is likely.

When to call a technician: Persistent icing requires professional testing of sensors, defrost logic, and refrigerant charge.

Hard 4/5

Outdoor Coil Temperature Sensor

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