isolating the leak where combi slowly loses pressure

[wayneyoung123]

My boiler is losing about 0.1bar of pressure a day..then i have to refill and reset the boiler to work.

Work already been done

Insurance company has replaced the PRV valve despite there never being any water coming out of the pipe. He respressurised something with a footpump. Then the company has refused to come back because the boiler is very bad condition, hasn't been serviced regularly and needs a powerflush! I have given up with them!(after 3 hours of pointless arguments)

I have just had a guy put in some sentinal selant into the system so hopefully that will help.

There is no dripping in the boiler cupboard itself.

How do i find the leak?
Can I isolate the boiler from the pipework by turning off the in/out flow at the boiler? If the pressure still dropped then i assume it would point a finger at the boiler losing pressure internally somewhere rather than in the pipework? Not sure how to find the relevant taps/valves to turn off this?

Can i turn off the radiators in the back half of the house...meaning that the boiler pressure gage can only be effected by a drop in pressure/leak in the rads in the front part of the house?. And then reverse this to see if it is the rads in the back half of the house.? How do i do this? Some of the rads have a dial which will turn off the water to that specific radiator but how do i stop the flow to subsequent rads. And how do I know what the layout it of the rads...ie. how they are linked together?

Boiler details
wocester 9.24 boiler - 17 years old
roughly 10 radiators/ground floor

 

[dextrous]

To be honest, give the age and condition of the boiler, I wouldn't be touching any isoltion valves on it.

Follow the pipes a few feet away and cut them there (you can always use compression or pushfit to re-join them).

As for where pipe runds go, the only way to be sure is to lift floorboards and look. It may be worth doing this anyway before you start cutting into pipes since the leak may become self evident.

As for your insurance company, I can see both sides of the argument.

 

[darren bergin]

take every trv head off and inspect

threre might be slight seepege from trv pin!

 

[wayneyoung123]

thanks for your replies..

I don't have any thermostatic valves.. just nobs that turn it on or off.

Also.. i did have some work done on the bathrooms a couple of years ago and the polish crew found an open tank of water above headheight (in the false celing) with a stopcok in it. they were confused and just bypassed it i.e connected the pipes either side of it.

I think this may be what is refered to an open system to a sealed system.

Have they gone and changed what was an open system to a closed system? is this a problem? could it cause a leak?thanks