Carrier Heat Pump Error Code 42: How to Fix It

Q: What causes Carrier error code 42?

Error code 42 is caused by a failure in the power inverter board that controls the variable speed compressor. Common causes include electrical surges, component aging, moisture infiltration, or manufacturing defects in the control board.

Q: Can I reset Carrier error code 42?

You can try resetting the error by turning off power for 5 minutes, but error code 42 typically indicates actual hardware failure that requires control board replacement. A simple reset will rarely fix this error permanently.

Q: How much does it cost to fix Carrier error code 42?

Fixing error code 42 typically costs $300-800 for parts and professional installation. The inverter control board alone costs $200-500, with labor adding another $200-400 depending on your location and the complexity of the repair.

Q: Is Carrier error code 42 covered under warranty?

Error code 42 may be covered if your heat pump is still under manufacturer warranty, typically within the first 5-10 years depending on your model. Check your warranty documentation or contact Carrier customer service to verify coverage.

Abstract

Carrier heat pump error code 42 indicates a power inverter board fault, which means the control board that manages the variable speed compressor has failed. This is a critical error that will prevent your heat pump from operating properly and typically requires replacing the main control board.