HF35 or HF36 — Micro-Electronic Component Failure

What does HF35/HF36 mean?

These errors indicate a micro-electronic component failure, typically meaning the slave thermostat's printed circuit board has failed. The system cannot function correctly due to an internal hardware issue.

• Internal failure of the slave thermostat's printed circuit board.

Click steps to track your progress.

1. 1

   Press any set point button on the slave thermostat to attempt a reset.

2. 2

   Try resetting the slave thermostat a few times to see if the error clears.

3. 3

   If the HF35 or HF36 error persists after multiple resets, the slave thermostat should be replaced.