ferroli he 31

[martin b]

Ive got a problem with a ferroli he 31 combi, the heating works until you turn on the hot water, when you turn off the hot water the boiler shows the code d1. now i know this is normal but this one does not return to heating at all. im looking at replacing the dverter valve. how much of the assembly do people replace, all of the valve including the motor, or just part of it?

 

[Plumb Ugly]

flow switch sticking?