Goodman HVAC Error Code 18: How to Fix It

Q: What causes error code 18 on a Goodman HVAC?

Error code 18 means the indoor coil temperature sensor is open (disconnected or failed). Common causes include a faulty sensor, loose wiring, or a blown fuse on the control board.

Q: Can I bypass the indoor coil temperature sensor?

No, bypassing the sensor is unsafe and will cause improper system operation. The sensor is essential for protecting the compressor and ensuring efficient cooling.

Q: How much does it cost to replace an indoor coil temperature sensor?

The sensor part typically costs $10-$30. If you hire a professional, labor may add $100-$200.

Q: Will error code 18 clear itself?

No, the error will persist until the underlying issue is fixed. Once the sensor is replaced or wiring repaired, you may need to reset the system by turning power off and on.

Q: Is it safe to use the AC with error code 18?

It is not recommended. The system may run inefficiently or repeatedly cycle on and off, potentially causing further damage. Schedule repair promptly.

Abstract

Error code 18 on your Goodman HVAC system indicates that the indoor coil temperature sensor is open (disconnected or failed). This sensor monitors the temperature of the evaporator coil and helps the system operate efficiently. When it's open, the system may run poorly or shut down.