Finding source of leak - heating pressure drop is this significant?

[farouqtaj]

I'm trying to find the source of a leak. There's a damp patch on an internal wall about 1m above floor level. I don't know if it's a leak from a pipe or ingress of water from outside. I've taken two readings of the heating system pressure one week apart. The Central Heating was not switched on. Only the hot water system. There is a slight drop in pressure but I'm not sure if this is significant enough to indicate a pipe leak.

Is it worth considering using a trace and access company that can fill the hot and cold water pipes with an inert gas and check for leaks using a special meter that detects small traces of the gas?

 

[terryplumb]

What is that immediately above the damp patch ??

 

[farouqtaj]

What is that immediately above the damp patch ??

The wall is downstairs in the hallway. Immediately above it is the landing. I have lifted the floorboards up and couldn't see any pipes running near it.

 

[terryplumb]

What is that immediately above the damp patch ??

The white and grey thing on the wall is what I was referring to .

 

[farouqtaj]

The white and grey thing on the wall is what I was referring to .

Oh that's just the control unit for the burglar alarm

 

[terryplumb]

The staining appears to start from it.

 

[mizuno]

I would not say that the pressure drop is significant enough to indicate a leak. There might be a slow drip somewhere in your system though.

Before using a company with tracer gas, check how much they charge. For that kind of money you might be better off buying a thermal camera, turning the heating on and then any leaks will be very apparent on the thermal camera. If the damp patch warms up with the heating on (might take a few hours depending on the severity of the leak), then you will know for sure that it's the heating system that's leaking

 

[Johntheo5]

Theoretically, it could be quite a leak but wouldn't rush off just yet.
A 8L E.Vessel if pre charged to 1.0bar and filled to 1.5bar will loose 0.21L in falling to 1.42bar, a 10L E.vessel will loose 0.26L. Its possible even if unlikely that the diaphragm is cracked and the water is leaking into the air space, if so, then the pressure rise will get higer and higher with the whole system heated up and E.vessel filling pressure kept at 1.5bar.

 

[ianmcd]

That pressure differential on the guage is perfectly normal , doubt very much if the heating system primary water is the cause of the stain, trac and trace companies are extortonate, you would be better and cheaper cutting a bit out of the plasterboard and seeing what is behind there, then replacing and decorating, will be a lot cheaper than a trac and trace