A0 - External protection active

What does A0 mean?

An external protection device has been activated, which is preventing the air conditioner from operating.

• External protection wired to T1-T2 is active.

Click steps to track your progress.

1. 1

   Check wiring to the T1-T2 terminals for any active external protection.

2. 2

   Ensure any external protection devices are correctly reset or disarmed.

3. 3

   Consult an HVAC professional if the issue persists.