Boiler has hot water, will fire up on Eco, it has everything calling for central heating and shows no fault code.

Is it possible for the mechanical diverting valve to stick on hot water? If so how do confirm this is the problem?

Do I need to buy the complete diverting valve including the actuator if it is at fault?

Any suggestions would be much appreciated.

Mark, December 2011

Yes they can stick, take cover off, you will be able to see valve, some have an actuator on one side going to micro switch, watch it does it move when hw called for, does it move back? If not stuck, possible to get overhaul kits for most makes, look on Ebay, But would depend on why it is not moving, Listen to it, can you hear some motor move.
If no switch on side, listen for it moving, usually hear it, switching water on/off Also check your pressure, should be about 1 bar cold.

SD, December 2011