Code 53 — Outdoor Air Temp Sensor Fault

What does 53 mean?

This fault indicates a problem with the outdoor air temperature sensor, affecting various systems including Furnace, Fan Coil, 18VS, 19VS/V-HP/AC, Greenspeed/Extreme, and Infinity/Evolution ODU units. The system cannot accurately read the outside temperature.

• Faulty outdoor temperature sensor
• Damaged or loose wiring to the sensor
• Sensor disconnected
• Control board unable to read sensor data

Click steps to track your progress.

1. 1

   Turn off the power to the outdoor unit at the circuit breaker for at least 30 seconds.

2. 2

   Restore power and observe if the fault clears.

3. 3

   Ensure the outdoor unit's sensor area is clear of debris or obstructions.

4. 4

   If the error persists, contact a qualified HVAC technician to inspect or replace the outdoor temperature sensor.