Bosch · Heat Pumps
The electric cassette for zone 1 has triggered its overheat protection or the system pressure switch has indicated low pressure (below 0.5 bar) in the air module. This prevents damage to the unit.
Click steps to track your progress.
Check the system pressure. If low, vent the heating system as per instructions in your manual and top up with water.
Clean the system filter/filter ball SC1. Refer to your manual for instructions on filter cleaning.
Review your heat curve and hot water temperature settings; adjust them if they are excessively high.
Ensure all adjuster valves and radiator thermostats are correctly set for good circulation.
If the alarm persists after these steps, contact a qualified technician for further inspection.