Main Combi 24 HE Rads On When DHW On

[ppk79]

Hi All,

As per the subject, we noticed rads have been heating up after running DHW for more than a few mins (such as after having a shower) even though the control is set to DHW only. We've turned the TRV's to 0 and closed the lock shields for now however would like to get this sorted before the cold weather arrives in case the heating packs up just when you need it.

Any ideas what could be the issue and is it a tricky job? If it involves gas, I'll leave it to a gas engineer however from what I've read, could be simple parts replacement that does not involve gas.

Any help would be greatly appreciated.

Thanks in advance.

 

[AGAS]

get a gas engineer

 

[dilalio]

Diverter valve issue. Not really a diy repair.

 

[ppk79]

Diverter valve issue. Not really a diy repair.

I've read these can be cleaned with a repair kit, is this worth it or best to just buy a replacement?

Thanks

 

[45yearsagasman]

There is a repair kit for these diverter valves, and for a skilled engineer it's straight forward. For a first time diyer, I would not recommend you tackling such a job. Great care has to be taken to make sure no water damages the electrics on the boiler. Its no more than an hours work to refurbish the valve with a kit. Many will say change the complete valve, but I've never done that and always refurbished, with no failures.

 

[ppk79]

There is a repair kit for these diverter valves, and for a skilled engineer it's straight forward. For a first time diyer, I would not recommend you tackling such a job. Great care has to be taken to make sure no water damages the electrics on the boiler. Its no more than an hours work to refurbish the valve with a kit. Many will say change the complete valve, but I've never done that and always refurbished, with no failures.

Thank you for the honest guidance, I certainly don't want to create more problems, just wishing to understand how this works in case I need to repeat this in future.

 

[AGAS]

I certainly don't want to create more problems,

You will

Thank you for the honest guidance, I certainly don't want to create more problems, just wishing to understand how this works in case I need to repeat this in future.

Your engineer will understand and all you have to do is pick up that phone

 

[Agile]

I always replace the whole diverter valve. If I charged for my time to recondition it the cost would be the same for the customer.

Once I did recon one because I was not busy and friends wife is nice and was looking after me.

I took great care, even boiling all the parts in citric acid to ensure they were totally clean. But even so it only worked for a few months.

Suspect the spring may become weak after a few years.

To

 

[45yearsagasman]

Once again, I repeat, It is not necessary to replace the whole valve, despite what the above says. Easy to dismantle in situ and replace parts. If you suspect a weakened spring, then that's included in the kits. Why replace a perfectly usable brass body. I, and I suspect many engineers can do these within the hour. Boiling parts in citric acid FFS is totally OTT.

 

[ppk79]

Thanks all for the speedy response, I'll get someone in to look at the diverter valve.

 

[dilalio]

Thanks all for the speedy response, I'll get someone in to look at the diverter valve.

Wise move IMHO. DIY'ing is a very big industry and I commend those who want to use their own hands in their own house. However, there's a huge difference between decorating a room, putting up a shelf and intricate engineering that has disastrous potential.
Rule of thumb should be... if it's money saving motivated, rather than a desire to learn and achieve, use a tradesman: it'll be cheaper in the long run!