Worcester GREENSOURCE User Manual page 32

What to do if a fault occurs
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.
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