There's a leak somewhere, but how to find?

[Sonyman]

We have a 4 year old combi boiler, which has been working well up untill we had some numpty try to fit a water meter to the hot water feed near the boiler and removed the pressure reducer from the cold feed, which caused a few joints to blow etc when we turned the heating on last September or so.
As the system is under a BG repair/maintenance contract we have had numerous BG men out to fix one problem after another when the heating failed to come on. Anyway now it does work ok, but the water pressure drops every now and again, and it has done this more frequently this last few weeks. Consequently I have to keep topping it up to get the heating to work again.
I cannot see anything obviously wrong nor water coming out anywhere, but I reckon there must be soem kind of leak for the fault to happen.

Any ideas as to how a leak can be found if its not obvious?
Thanks

 

[Fluffster]

Do you your pipes run under concrete floors or under wooden floors on the ground floor?
Pete

 

[Sonyman]

The pipes run under wooden floorboards. Mmmm, that sounds ominous!

 

[Fluffster]

If you have no obvious signs of a leak it maybe leaking under the floorboards below making it undetectable to you, esp if you live in a victorian house where there is soil below.
Pete

 

[Sonyman]

The house is a 1930's build with soil under the house. Yes you could be right there about it leaking under the house. I didn't want to think that as access is a bit tight to underneath, but we'll see what the next visit from the gasman brings

 

[Slugbabydotcom]

Stick a container under or tie a bag round your PRV pipe to be sure it isnt coming out of there when the system is warming up.
I hope for your sake that you dont have any laminate floors!

 

[doitall]

well said slugbabydotcom.

Leak my ar se he has a drip somewhere possibly a radiator valve gland nut or the PRV.

 

[Sonyman]

Ok guys, thanks for the replies, and I will do as suggested, but first of all what is a prv?

Just out of interest, I have not had to top up the boiler now for that last 7/8 days.

Thanks

 

[doitall]

PRV = pressure relief valve, the thing on the end of the pipe that stick out the wall

Tie a balloon over the pipe to check for drips as the boiler heats up.