Wiring Diagram for a BAXI WM 511 RS boiler needed

BAXI WM 511 RS wiring diagram?

I have a problem with my BAXI boiler. When the water is on, heating off, the water and heating come on, and when the heating is on, water off, the water and heating come on. Also, strange bubbling noises come from the header tank. This is worrying so i have turned it off!
Any Ideas to what is the problem? Does anyone have a wiring diagram? Please send me the link so i could print it off?

My uncle is a plumber and he reckons the 3 way valve is the problem but it is due to the electrics
Thanks

I think your uncle could be right. When in heating only your controller sends a signal to the valve so that it opens the heating port and lets hot water pass to your radiators. As it opens, via switches on the valves it also starts the pump/boiler.

When in heating & hot water your controller sends a signal to the valve to open the heating and hot water ports which then heats up you hot water tank as well. When the tank is up to temp the tank thermostat opens and the valve goes back to the heating port only.

It sounds like both ports are open all of the time. As the valve is not closing when the hot water tank is up to temp the water within the tank will get hotter & hotter. I suspect the noise you can hear is the water starting to boil in the tank.

The motors on valves don’t last forever but you can normally get a replacement and swap it over. If the complete valve needs changing it may well be a job for a plumber.

You’ve done the right thing turning it off because when the water boils it can overflow via the expansion pipe into your cold water storage tank and over time that can get very messy.

Thanks for the detailed reply, especially about turning it off.

Is it a easy job to swap the motor?