Unvented system appears to be losing pressure

[alexb123]

Apologies for lack of proper terminology, I don't know much about this-
We recently had our bathrooms re-done, but not sure if this will be related.

This pressure gauge seems to lose pressure (black needle has dropped)-



When I turn the two little black valves to the left, the black needle rises.

However, a couple of days later, it's returned to where it is now.

There's no obvious signs of a leak anywhere.... no water through ceiling, or anything like that.

The water pressure also seems ok on taps.

Any ideas what else could be causing this?
Or anything else I should be looking for?

 

[Riley]

This could be a number of things. It will be on the heating side as you say and could be a leak at a radiator or one of the safety devices doing its job. Best advice would be to get an engineer out to take a look

 

[alexb123]

thanks for the reply!
i've checked the rads for obvious leaks -
Only thing I've noticed is one (just one) doesn't get warm at all, which is a bit weird

I'm covered by british gas, so think they'll get a call in the morning!

 

[Riley]

Yeah best way mate. It will hopefully he something simple. Let us know how you get on

 

[joni os]

Check for leaks with system cold. Slight leaks often evaporate on hot pipework. Rise pressure to 2 bar and spread newspaper below boiler in case that is source of leak. Leave for one hour then with bright light inspect valves on radiators especially the spindle and any compression fittings for sign of leakage. Reduce pressure to 1 bar by venting at radiator before turning heating back on.
If you fail to find leak or spot on newspaper indicates boiler, call in Gas Safe Engineer( as above).

 

[chris watkins]

Have you checked for signs of water discharge from the pipe leading away from the red headed valve under the pressure gauge in your photo ? You may need to go out doors to find its end.

So long as the gauge does not drop any lower that that shown you should be OK but it might be a sign that something need adjusting on the system.