Alarm Z1 5463 - Defrost failure. Clean outdoor unit

What does 5463 mean?

This alarm indicates that the Heat Pump's defrost function is failing. This can be caused by excessive ice on the evaporator, issues with the heating system's temperature, or a clogged filter.

• Evaporator on the outdoor unit clogged with ice.
• The Heat Pump system is overfilled with water/refrigerant.
• Too low temperature in the heating system due to closed thermostats.
• Dirt or debris in the system filter/filterball SC1.

Click steps to track your progress.

1. 1

   Gently melt any ice on the outdoor unit's evaporator using hot water (do not use sharp objects).

2. 2

   Ensure enough thermostats in your heating system are open to allow for proper water flow and temperature.

3. 3

   If you can access it, check and clean the system filter/filterball SC1.

4. 4

   If the alarm persists, contact a qualified Bosch Heat Pump installer.