Trane HVAC Error Code 13: How to Fix It

Q: What does error code 13 mean on a Trane HVAC system?

Error code 13 on a Trane HVAC system indicates a fault with the return air temperature sensor. This sensor monitors the temperature of air returning to the unit from your home. When it fails, sends an out-of-range signal, or loses its wiring connection, the system logs code 13 and may reduce or shut down operation to prevent incorrect temperature control.

Q: Can I run my Trane HVAC with error code 13 active?

It is not recommended. While the system may continue to operate in some cases, it cannot accurately read return air temperatures, which means it may overheat, overcool, short-cycle, or fail to maintain your set temperature. Running the unit in this state for extended periods can put additional stress on the compressor and other components.

Q: How do I reset error code 13 on a Trane system?

After fixing the underlying issue — such as reconnecting a loose wire or replacing the sensor — turn the thermostat to OFF, then shut off the HVAC circuit breaker for 30 seconds. Restore power and turn the thermostat back on. Most Trane systems will clear the fault automatically once the sensor is functioning properly and the unit completes a normal operating cycle.

Q: How much does it cost to replace a Trane return air temperature sensor?

The sensor itself typically costs between $15 and $60 depending on your Trane model. If you hire a professional HVAC technician to do the job, expect to pay an additional $75 to $150 in labor, bringing the total to roughly $90–$210. DIY replacement can save significantly on labor costs.

Q: Why does my Trane keep showing error code 13 even after replacing the sensor?

If error code 13 returns after replacing the sensor, the issue may be with the wiring harness between the sensor and the control board, a faulty control board that is misreading the sensor signal, or an incompatible replacement sensor. Check that the new sensor is the correct part for your model, inspect all wiring for damage, and consider having a technician test the control board.

Abstract

Trane HVAC error code 13 indicates a fault with the return air temperature sensor — the component responsible for measuring the temperature of air being pulled back into your system from your home. When this sensor fails or sends an incorrect signal, your Trane unit can no longer accurately regulate heating or cooling, triggering the fault code. In many cases, this is caused by a loose wire connection, a dirty sensor, or a failed sensor that needs replacement.