DIY Doctor UK DIY Forums

I recently paid a local firm to replace my heating system, I had a tanked system and now have a combi boiler. The boiler shuts down due to loss in pressure most days ands sometimes twice in a day. The plumber has done some investigating work and believes it’s a leak under the ground floor floorboards which has either been there a long time or the new pressurised system has caused a leak or multiple leaks. He said it’s an Insurace job (mine) as all the wooden flooring and then floorboards on the ground floor need to be taken up and the finished floor would probably need to be replaced. My insurance company said no as the floor isn’t water damaged. My question is should the plumber advise me first that changing the system to a pressurised one could create leaks under the house and cost another £10k to fix (on top of £5k for the boiler) and should I insist he does all this work through his insurance? I have a heating system that doesn’t work properly and wake up to cold radiators most mornings yet have already paid £5k for this disaster. Is this just life and I’ll just have to take a loan out and pay for it all or is it more neglect from the plumber? Thanks in advance for any help and apologies for it being a bit longwinded, I have no where else for help!

The old lock shield valves often leak with the extra pressure of a sealed system, so it is common to have problems when changing, however although one feels he should have tested old system including flushing it out, and should have advised you of any likely problems, he has not fitted those pipes, so can't see how you can claim from him for workmanship not done by him?

I have had a poor soldered joint where some flux has sealed the joint to start with, start to leak later, and even had a pipe with a floor board screw through it not leak to start with but leak latter, but the leak has been far more than needing to top up once a day.

I have also had it where the expansion vessel was not large enough, in that case each time the heating cooled down it would fail to start again, same where the expansion vessel has failed or has not been charged with gas.

If the expansion vessel is at fault, then if you don't run central heating the pressure will not drop. If using old pipework then it is a little bit of guess work on size of expansion vessel required, and the one built into boiler may not be large enough.

Thanks ericmark, do you think it’s worth putting one of these sealing solutions in the system or do they clog it all up in the future?