Finding a leak in the central heating system?.

[Sherco290]

Hi, I clearly have a leak somewhere in the CH sytem as the water pressure is being lost quite quickly after filling so obviously I'm not using it. It seemed to happen quite suddenly, nothing showing upstairs or on downstairs ceiling, so appears to be under downstairs floor.
I'm unlikely to get a plumber for a month or two until Covid restrictions are lifted a bit, but just for interest, how does the plumber detect a leak under the floor?.

 

[HERTS P&D]

I'm unlikely to get a plumber for a month or two until Covid restrictions are lifted a bit, but just for interest, how does the plumber detect a leak under the floor?.

What you chatting about?

I'm on call now, if the phone rings, I'm going to work.

Make some phones calls, get some prices.

Andy

 

[footprints]

If a pressurised system check the safety valve is not discharging, a 15mm pipe on the outside wall somewhere. Might be a faulty valve or expansion vessel allowing over pressurising.

 

[ianmcd]

set boiler pressure to 1-1.5 Bar when cold , turn heating on and ch and check the pressure again after 30 mins and see what the pressure is now at, if near 3 Bar you have an expansion problem not a leak

 

[Sherco290]

Sorry, I should have said, it's a sealed system with external high level expansion vessel. Expansion vessel is free of water and pressurised. No water escaping through tundish.
I was wakened one morning about 30 mins after CH came on, by the sound of air in the radiator beside the upstairs bed. Checked the water pressure gauge which was below 1, topped up, bled radiators and switched CH back on, about an hour later the pressure was down to 1 again, so all turned off. I suspect a sudden leak under downstairs floor, can't see anywhere else water could be escaping unless maybe a leak in the coil inside the cylinder but the DHW is quite clean and no smell off it.

 

[HERTS P&D]

Get a thermal camera.

Andy

 

[Sherco290]

Andy, never thought of that, we have a very expensive and powerful TI riflescope and binos, I'll give them a try. Thank you.