On Friday, 3 May 2019 16:14:04 UTC+1, Davidcorlett wrote:
replying to tabbypurr, Davidcorlett wrote:

I see what you're getting at. Am just wondering if I could do it more simply.
Just get the boiler to pump when the tap is opened, but not fire up? I am
guessing that the control unit would be the point of focus but after all, if
the drop or flow caused by the opening of the tap causes a sensor to then run
the pump and ignite the boiler, I just want to block that firing up.
All manuals do the fault diagnosis and fix to create the ignition, not to stop
it.

Will keep thinking.
Thanks for all the advice. Very much appreciated.
David

I doubt you can modify what it does & not have it shut down reporting a fault.
You might just get away with heating its internal store externally, maybe. That way it doesn't need to do anything outside its usual routine.


NT