5526 - Bosch Heat Pump Z2 defrosting system alarm: Clean outdoor part

What does 5526 mean?

This alarm indicates that the defrosting cycle for Bosch Heat Pump zone 2 has exceeded its normal time or required too many attempts. It triggers if the timer for defrosting exceeds 800 seconds 3 times, or if 3 defrostings are needed in minimum time for heat production.

• The outdoor evaporator unit is blocked with ice, preventing effective defrosting.

Click steps to track your progress.

1. 1

   Carefully inspect the outdoor unit's evaporator for any ice buildup.

2. 2

   Gently melt any ice on the evaporator using hot water; do not use sharp objects or chemicals.

3. 3

   Ensure that there is clear airflow around the outdoor unit by removing any obstructions like snow or leaves.

4. 4

   If the alarm recurs, contact a qualified technician to investigate the defrosting system for proper operation.