4230 — Heat Sink temperature trouble

What does 4230 mean?

This code indicates that the thermistor (TH8) monitoring the heat sink temperature is detecting a temperature outside its normal operating range during compressor activity. This usually suggests that the heat sink is not being adequately cooled, which can lead to overheating.

• Blocked outdoor fan or a malfunction of the outdoor fan motor.
• Obstacles (e.g., debris, dirt, overgrown plants) blocking airflow around the heat sink.
• Abnormally high ambient temperature around the outdoor unit.
• A faulty heat sink thermistor (TH8) or issues with its wiring or input circuit.

Click steps to track your progress.

1. 1

   Check if the outdoor fan is rotating properly and freely when the compressor is operating. Ensure there are no obstructions preventing it from spinning.

2. 2

   Inspect the outdoor unit thoroughly for any obstacles (like leaves, dirt, or debris) that might be blocking the airflow around the heat sink fins and clear them away.

3. 3

   Verify that the wiring and connector for the TH8 thermistor on the outdoor unit are securely connected and free from any visible damage.

4. 4

   Turn off the main power to the unit at the breaker, wait for a few minutes, then restore power to reset the system and see if the error clears.