Warning Z1 5453 - No power supply to outdoor unit

What does 5453 mean?

This warning occurs if the incoming AC voltage to the outdoor unit's inverter drops below 165 V for 10 seconds. It will automatically reset after 2 minutes if the voltage returns above 190 V.

• Low or no voltage supplied to the outdoor unit.
• Poor contact or blown main fuses for the outdoor unit.
• Low incoming mains voltage from your electricity supplier.

Click steps to track your progress.

1. 1

   Check the main fuses in your electrical panel that supply power to the outdoor unit. Replace any blown fuses.

2. 2

   If warnings repeat frequently, contact your electricity supplier to check the incoming mains voltage to your property.

3. 3

   If the issue persists, contact a qualified Bosch Heat Pump installer to inspect the electrical connections.