New Boiler Losing Pressure

[ristac]

So we’ve moved into a rural 70s property and one of the first things we had done, a new system boiler and radiators. For the first two weeks no problem, for the last 7 days we’re losing pressure, we’re talking between 1 to 2 bar a day.

The guys who fitted it can’t find anything wrong, they’re coming back tomorrow to pop isolation valves on to cut off the boiler from the house pipe work as they’re adamant we must have a leak in the pipe work under a tiled and concrete kitchen floor.

It’s an Ideal boiler, they did move a pressure release valve/tank from the airing cupboard to the garage and next to the boiler itself, they’ve already said if the boiler doesn’t drop pressure when they isolate it for 24 hours then it can only be a leak in the concrete pipe work.

I asked how much is 1 bar of pressure a day, they said a litre, surely that would show signs under the tiles or not

 

[itsallaboutyou]

Can a boiler be pressurised with loads of air already existing in the system? So - the air is now managing to escape as the hot water circulates causing the pressure drop??

Full drain and refill / mega bleed perhaps?

Fluid mechanics clearly not my thing!

I know ordinarily it would signify a leak somewhere?

 

[darael]

I'd go round and bleed all your radiators. While bleeding, if any air seems reluctant or slow to come out then make sure the pressure at the boiler is at least 1.0 bar before continuing - some like it a bit higher, so check the manual. One you're finished, check the pressure at the boiler again and top up via the filling loop if needed.

My own suspicion is that they've weakened a joint near the boiler during installation.