Hi, a common theme here I know, there is always someone with a plumbing problem.

My central heating only works when the hot water is working. When the hot water is up to heat, the central heating immediately stops heating and the radiators cool until e.g. someone takes a bath.

When the central heating is switched off but the hot water is on, the radiators still heat up. You can't run the central heating at all if you only switch on the heating and not the hot water.

Hopefully there is a heating genius out there to help me figure out the problem. We have changed the motorised valve and it's controller and the pump is working fine.

Got a feeling it's something inside the boiler (a Vaillant).

Any help very gratefully accepted, if you save me from having to buy a new boiler I would love to buy you a few pints before a match.

If it were me, I would suffer with it and get through this winter then change to a combi.

You will save in the long run and the Government do a scrappage scheme

Paua oouaarancì Irà chiyeah Ishé galé ma ba oo ah

Good food for thought, many thanks PP

Have you tried turning it off and on again ?

As far as the rules go, it's a website not a democracy - Hambo 3/6/2014

Sounds like a wiring fault in regards to the diverter valve. I'm assuming you have one valve with three ports going to it? I'd recommend getting a professional round that you can trust... It's not going to be something you can fix yourself (with respect)

I find that with boiler problems if you leave them for long enough they fix themselves or worst case scenario you learn to live with the problem and adapt your life accordingly e.g. having a bath every time you want the heating on doesn't sound too bad.