Danfoss - heating water

[JohnMalcolm]

Hi All,
I hope you are well. I have Danfoss CP715Si controller and when I try to heat water the boiler does not kick in.
When I select Hot Water to ON or press +1HR button to turn it on for one hour the red light comes up on the controller but the boiler does not kick in.
It does kick in when I turn the heating on.
What could be the problem?
Thanks

 

[cjg]

port valve fault?

 

[JohnMalcolm]

port valve fault?

Is this to do with the boiler (in my case Baxi Solo 15 HE) or the boiler.
I admit I did lower the water heating temperature from 60 to 40 as I don't need that hot water.

 

[Basher]

As per CJG
The switched live power for your boiler comes from a 2-port or 3-port valve that controls the water flow.
If the valve fails or gets sticky and doesn't move fully over in its travel, the microswitch in the motorised valve head does not operate, and the boiler won't fire.
So a faulty of intermittent motorised valve will cause the symptom you describe. It's not necessarily anything to do with the programmer or boiler itself