Alarm Z1 5375 - Risk of frost in condenser

What does 5375 mean?

This alarm is triggered if the 'Risk of frost in condenser' warning (code 5374) occurs repeatedly (3 times within 3 hours) or remains active for 30 minutes, indicating a critical and persistent risk of frost damage.

• See possible causes for warning code 5374 (Insufficient circulation, clogged filter, air in system, sensor failure, pump or module issue).

Click steps to track your progress.

1. 1

   Note the alarm code 5375.

2. 2

   Immediately ensure all radiator thermostats and adjustment valves are open to maximize flow.

3. 3

   Check and clean any accessible system filters, and thoroughly de-air your heating system, ensuring it's topped up with water.

4. 4

   Contact a qualified Bosch Heat Pump installer or service technician immediately, as this is a critical alarm.