by ericmark »
Fri Mar 26, 2021 3:10 pm
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.