86 — Heat sink temperature trouble

What does 86 mean?

This error indicates an abnormal temperature reading on the heat sink, which is critical for dissipating heat from power components. An overheated heat sink can lead to component failure.

• Restricted airflow around the heat sink.
• Dirty or clogged heat sink fins.
• Faulty thermistor (temperature sensor) monitoring the heat sink.
• Issue with the power module causing excessive heat.

Click steps to track your progress.

1. 1

   Ensure that the outdoor unit is free from any debris, dirt, or obstructions that could block airflow around the heat sink.

2. 2

   Gently clean the heat sink fins if they appear dirty or clogged with dust.

3. 3

   Verify the outdoor unit fan is operating properly to dissipate heat from components.

4. 4

   Power cycle the unit by turning off the main power supply for several minutes, then restart.

5. 5

   If the error continues, a technician should check the heat sink thermistor and power module.