Boiler problem

Agusya

Ive just noticed that when Im having shower (which comes off the gas combi boiler) radiators are heating up. Ive looked it up and can see possibly faulty diverted valve. But my question is - is it possible that the water used / heated up during the shower is just some kind of reserve being produced during the shower and going into radiators and its just normal in this case ? Is this a thing? Ive never noticed it last summer probably cos radiators were switched off . Thanks! 

FreeBear

Radiators should never be heating up when running hot water with a combi - There is a diverter valve inside the boiler to prevent this from happening. Get your local Gas Safe engineer to take a look, and don't try to fix it yourself.

ThisIsWeird

Agusya said:

Ive just noticed that when Im having shower (which comes off the gas combi boiler) radiators are heating up. Ive looked it up and can see possibly faulty diverted valve. But my question is - is it possible that the water used / heated up during the shower is just some kind of reserve being produced during the shower and going into radiators and its just normal in this case ? Is this a thing? Ive never noticed it last summer probably cos radiators were switched off . Thanks! 

Hi Agusya.
If the radiators are actually 'heating up', then that is a fault. Even if the CH 'flow' pipe from the boiler becomes 'hot', that is too much.
Yes, you might feel the CH pipe becomes warm at some point during DHW use, but it should only be localised.
And you are almost certainly right in your suspicion - diverters do stick and wear over time and would then cause this literal issue.
Q - do you have a magnetic filter fitted? Have you checked it recently. This can be caused by a coating of sludge, so worth having that checked too.

Agusya

FreeBear said:

Radiators should never be heating up when running hot water with a combi - There is a diverter valve inside the boiler to prevent this from happening. Get your local Gas Safe engineer to take a look, and don't try to fix it yourself.

Will something going to happen if I dont fix it ? 

FreeBear

Agusya said:

FreeBear said:

Radiators should never be heating up when running hot water with a combi - There is a diverter valve inside the boiler to prevent this from happening. Get your local Gas Safe engineer to take a look, and don't try to fix it yourself.

Will something going to happen if I dont fix it ? 

Wasting gas, which will cost you money, especially during the summer months. There is also the chance that debris from the radiators could get dragged in to the P2P heat exchanger and clog it up especially if you don't have a magnetic filter installed. If the P2P heat exchanger does get clogged, you won't get hot water and incur a bigger repair bill.

Best to book a service and tell them that the diverter may need changing. This time of year, it won't be an urgent repair, so you can avoid any emergency call out fees.