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Possible cause 3: The underfl oor heating or radiator valves are
closed.
Action: 1. Open the valves.
Possible cause 4: The fl ow across the heat pump is greater than
the fl ow in the heating system.
Action: 1. Reduce the speed of the heat carrier pump (see
Tripped high pressure switch) or increase the speed
of the circulation pump for the heating system.
Contact your dealer for help.

Additional heat is now working at its highest

permitted temperature

There is a sensor T9 in the heat pump, which for reasons of safety, stops the
compressor and limits the additional heat to the heat pump if the tempera-
ture of the return water from the heating system becomes too high. The
limit for additional heat lies at approximately 48ºC.
Possible cause 1: The heat setting is set so high that the heating
system’s return temperature is too high.
Action: 1. Reduce the heat curve setting.
Heat carrier pump
(290 A/W)
Circulation pump
for the heating
system (290 A/W)
What to do if a fault occurs