Mitsubishi Heat Pump Error Code U5: How to Fix It

Q: What does Mitsubishi heat pump error code U5 mean?

Error code U5 indicates an inverter heatsink temperature fault, meaning the inverter's cooling system has overheated due to blocked airflow, dirty coils, refrigerant issues, or component failure.

Q: Can I continue using my heat pump with a U5 error?

No, you should immediately turn off the system when U5 appears. Continued operation can cause permanent damage to the compressor and inverter board, leading to expensive repairs.

Q: How much does it cost to fix a Mitsubishi U5 error?

Costs vary depending on the cause. Simple cleaning may cost $150-300 for a service call. Inverter board replacement can cost $800-1500, while compressor replacement may cost $2000-4000 including labor.

Q: How often should I clean my Mitsubishi heat pump to prevent U5 errors?

Clean the outdoor coils at least twice per year (spring and fall) and keep the area around the unit clear of debris. Monthly visual inspections during heavy use seasons can help prevent overheating issues.

Q: Is the Mitsubishi U5 error covered under warranty?

Coverage depends on your specific warranty terms and the root cause. Component failures within the warranty period are typically covered, but damage from lack of maintenance or external factors may not be covered.

Abstract

The Mitsubishi heat pump error code U5 indicates an inverter heatsink temperature fault, meaning the inverter's cooling system has overheated or failed. This is a serious issue that can damage the compressor and other components if not addressed quickly.