Hot water use makes all radiators be heated - why?!

[carolined79]

Short version - if I use any hot-water, through taps, shower or the washing machine, the central heating kicks in and all the radiators come on throughout the house. I don't think this is right and do have quite high gas bills considering generally conservative usage. It's a Worcester Combi Boiler - I can check specific model if that would help.

Long version - boiler was in the property when I moved in two years ago. Only problem occurred when there seemed to be a significant loss of pressure in hot water for the shower. Called a plumber out who replaced a big bottom cartridge looking bit (I really apologise for my lack of knowledge on this). It cost me £400 and flow did improve a bit. I don't 100% recall whether the radiators came on before this was done but I have a feeling they did.
There is a small red valve below the boiler main-body which I can open to push the pressure needle back up to where the red one is, however I generally tend to try not to touch anything.
The people in the property before me seem to have been diy-enthusiasts without great skill. There are a number of oddities with the wiring etc and the plumbing looks a bit home-grown. I tried to join a contract home-care scheme for central heating but because of how the boiler has been put on the wall it is not acceptable for accessibility reasons.

If this shouldn't be happening with the radiators I'd really appreciate any advice on what's happening, as you may already have gathered I really am lost at this stuff which makes it very hard to know decent quotes and workmen.

Many thanks,
Caroline.

 

[mickyg]

most likely diverter valve. If its the brass gianonni valve on an older cdi model it can sometimes be a pain to change. If you haven't got a good, local boiler repair engineer then a fixed price job from worcester or BG might be an option.

 

[mattylad]

If it is the same brass gianonni valve then searching my posts will bring up a supplier of them where the valve is under £40.

 

[carolined79]

Thanks for the really quick reply - can I just check that I'm right in assuming this would be increasing my gas usage?

 

[mickyg]

heating radiators when not required will use more gas than you need to, yes. How much is difficult to say. Also are you measuring your gas usage in units or in £££ ?

 

[carolined79]

Cheers, this really helps me feel a bit more comfortable when getting local quotes. Thanks so much for the help,
Caroline.

 

[mickyg]

Cheers, this really helps me feel a bit more comfortable when getting local quotes. Thanks so much for the help,
Caroline.

why don't you try worcester? they can offer a fixed priced repair. They will most likely have the part on the van, will have done the job many times before and quite often be cheaper than everyone else.