5377 - Bosch Heat Pump Z2 freeze protection of condenser alarm

What does 5377 mean?

This alarm indicates that the condenser in Bosch Heat Pump zone 2 is at risk of freezing. It triggers if the temperature sensor TC3 is below 5°C. The alarm resets when TC3 and TC1 are both above 7°C. This alarm activates after 3 warnings in 3 hours, or if a warning is active for 30 minutes.

• Extremely low outdoor temperatures.
• Insufficient heat transfer causing condenser temperature to drop.
• Faulty temperature sensor (TC3).

Click steps to track your progress.

1. 1

   Check the current outdoor temperature to see if it's exceptionally cold, which can trigger freeze protection.

2. 2

   Ensure the Heat Pump is operating in heating mode and not in standby or off.

3. 3

   If the alarm persists, contact a qualified technician to inspect the condenser and relevant temperature sensors.