New Boiler losing pressure

newellan · 6 Sep 2006

I have just had a new condensing boiler installed (Grant) as the last one completely died asfter 20 years. The system is now pressurised whereas before it was gravity fed, in six weeks I have lost the 1 bar pressure that I had and the plumber from the company who installed it, started telling me about leaking pipes under the floor etc...which sounds very costly.
I have had a quick look around the tank in the loft and most of the visible pipes/radiators and have found 3 radiators (out of 13) which are 'damp' around the valves at the bottom - I wouldnt say wet but just damp. My 6 million dollar question is could this have caused the loss of pressure or am I looking for a major leak?

thank you

bster · 6 Sep 2006

When we change a tank fed heating system to a sealed (pressurised) system we always change all the rad valves, and we dont install to existing pipes under the floor - usually put new drops\runs to rads.

So it may well be worth changing the rad valves if you think they are leaking - how old are the rad valves?

The installer should be sorting all this out though - they should have told you about the possibility of leaks under the floor and given you options on new pipe runs above floor level etc..

newellan · 6 Sep 2006

In addition to the above the brand new programmer stopped working and when a new one was fitted that blew as well...I was told that it was probably the room thermostat (the only bit that wasnt changed by this company), this all happened with an accompanying intermittant schreeching sound (ie the boiler stopping and the programmer 'blowing'). The programmer only blew when I switched it to heating as well as hot water though.

hopefully some has some good news....

thanks

newellan · 6 Sep 2006

The radiator valves are at least 20 years old I think...

I wasnt given an option of new pipes but I was told that there could be a problem, so we paid for the whole system to be tested to 2 bar pressure before starting the whole process (the test was carried out by the same company etc)

thanks

bster · 6 Sep 2006

Well i'm not sure that 2bar test is sufficent as the pressure from cold is 1-1.5bar and its probably running to 2.5bar when hot!

If the programmer they installed is playing up and they say its probably the roomstat - change the room stat - bearing in mind that some boilers and programmers require specific voltages - they should have checked this as well.

newellan · 6 Sep 2006

They came and put another programmer on and then that one blew that was when they said it was probably the room stat...they are coming back today..

thanks again

plumber (new blood) · 6 Sep 2006

you have leak thats the sure thing here, slow oone but its there.

sometime dirt can stick in the P.R.V and cause pressure to drop.

is the discharge dripping, and that not the condensate discharge.

as for the electrics?? maybe a wiring fault in the system, old wiring to the stat ect...

a sparky would be the best person to sort that one.

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New Boiler losing pressure

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