Vailliant sustain 418 heat only problem

[diycooper]

Well, that's odd, because originally boiler would not fire for hot water. Can you post a photo of the pcb wiring and the front of the boiler? As per @Mottie - It should be your installer sorting, not you.

Yes l thanks I agree it should be installer. It's in a rental also so bit more of a problem.

I'll get a picture when can attend .

Sounds unlucky but if wired right at boilor and 240 v is not switching on and off at boilor on ch and hw so permanent live ( which I don't know is case yet).

Could the 3 port head of gone causing a permanent live.

So this would need checking the orange wire on y plan is switching 230v to 0 when turn controls on and off ?