Pressure Leak

[Humble]

Around two years ago i had a subsidence problem with my outside building
4 months ago it was knocked down and rebuilt with the boiler being replaced with a new combo boiler.
Since the work my bolier loses pressure after about 3-4 hours with no sign of a water leak in the house or outside building.

I have had a couple of plumers look at it but i am no nearer a resolution.
Is there anyway of narrowing down where the leak maybe and if it would definetly be a water leak rather than an air leak

 

[Bahco]

You need to go over all your joints with a toothcomb.
Try coloured tissue paper around each joint and you may have to get floorboards up in your hunt.
Also check your PRV pipe under your boiler leading to outside is not leaking.
You do need to find it I'm afraid
Happy hunting.

 

[ChrisR]

If you've been topping up twice a day for 4 months you will have introduced a lot of oxygen in the new water which will almost certainly give you problems with sludge/rust.