Operation LED blinks 4 times, Timer LED blinks 2 times, and wired remote shows 42 — Indoor heat exchanger (pipe) thermistor error.

What does Operation 4 Times / Timer 2 Times / 42 mean?

The thermistor that detects the temperature of the evaporator pipe in the indoor unit has identified an abnormal temperature.

• The indoor heat exchanger pipe thermistor is open (disconnected) or shorted (faulty connection).
• The controller PCB is defective.

Click steps to track your progress.

1. 1

   Power off the indoor unit at the circuit breaker.

2. 2

   Visually inspect the thermistor and its wiring for any damage or loose connections.

3. 3

   If the error persists, professional service is needed to check the thermistor's resistance or the controller PCB.