Bosch Heat Pump Error Code EA 408: How to Fix It

Q: What causes Bosch heat pump error EA 408?

EA 408 is caused by a faulty outdoor air temperature sensor. Common causes include damaged sensor wiring, a defective sensor probe, corrosion from weather exposure, or loose electrical connections.

Q: Can I run my Bosch heat pump with EA 408 error?

While the system may still operate, it won't function efficiently and may not switch between heating and cooling modes properly. It's best to fix the error promptly to prevent higher energy bills and potential damage to other components.

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

The sensor itself typically costs $15-50, while professional installation can range from $150-300 depending on your location and the complexity of the repair.

Q: How often should outdoor temperature sensors be replaced?

Outdoor temperature sensors typically last 8-15 years. They may need replacement sooner if exposed to harsh weather conditions, physical damage, or electrical surges.

Q: Will EA 408 error affect my energy bills?

Yes, this error can significantly increase energy costs because the heat pump cannot efficiently determine when to switch operating modes, potentially causing it to work harder than necessary.

Abstract

Error code EA 408 on your Bosch heat pump indicates a malfunction with the outdoor air temperature sensor. This sensor is crucial for your heat pump to operate efficiently, as it helps the system determine when to switch between heating and cooling modes. While this error may cause reduced performance or prevent the system from operating properly, it's often fixable with some basic troubleshooting.