R
rytenuff
Vokera 14e losing pressure. (Bungalow)
Replaced heat exchanger, both HW and CH motorised valves and actuators, PRV, expansion vessel, high limit thermostat, both inlet and outlet service valves and circuit board.
No above floor leaks apparent.
Switched off electrical power to unit. With system cold, pressurised system to 1bar and closed both (brand new) service valves, pressure went down within 2 hours to 0.5bar. Removed boiler covers so heat exchanger visible to check for any signs of water. None apparent anywhere. No water dripping from PRV or any joints in the boiler. Where is the water going!
Attempted to let water in via loop with the service valves closed. No water allowed in. IE no flow heard. (Think this would show if (new) service valves were bypassing water?) Closed loop again.
When return service valve opened, pressure returned to 1bar but dropped soon after when closed again.
Doing this repeatedly the pressure eventually dropped to 0.25bar.
When new pressure vessel fitted (8L, original rated at 4.5L) and system refilled to 1bar, upon firing up the system, the pressure rose rapidly to 2.25bar and the PRV dripped. Brand new expansion vessel is holding (nitrogen) pressure so why did it not accomodate the increased pressure. The flexi hose was checked for blockages before fitting . PRV stopped dripping when the pressure fell to 2bar.
As long as the radiators, which all heat properly no cold spots, are operating. IE the timer is set to ON, the pressure remains fairly constant. It drops to almost zero when CH timer goes to OFF.
The usual tests which I have performed as per advise don't seem to give the expected results.
E.G.
Closing the service valves should show whether it is the boiler or pipework at fault.
Rapid rise in pressure points to expansion vessel.
I'm at a complete loss and very frustrated by all this. I feel the leak is under the floor but there is no access. I don't want to tear up carpets , laminate and flooring until I am sure.
Any ideas?
Replaced heat exchanger, both HW and CH motorised valves and actuators, PRV, expansion vessel, high limit thermostat, both inlet and outlet service valves and circuit board.
No above floor leaks apparent.
Switched off electrical power to unit. With system cold, pressurised system to 1bar and closed both (brand new) service valves, pressure went down within 2 hours to 0.5bar. Removed boiler covers so heat exchanger visible to check for any signs of water. None apparent anywhere. No water dripping from PRV or any joints in the boiler. Where is the water going!
Attempted to let water in via loop with the service valves closed. No water allowed in. IE no flow heard. (Think this would show if (new) service valves were bypassing water?) Closed loop again.
When return service valve opened, pressure returned to 1bar but dropped soon after when closed again.
Doing this repeatedly the pressure eventually dropped to 0.25bar.
When new pressure vessel fitted (8L, original rated at 4.5L) and system refilled to 1bar, upon firing up the system, the pressure rose rapidly to 2.25bar and the PRV dripped. Brand new expansion vessel is holding (nitrogen) pressure so why did it not accomodate the increased pressure. The flexi hose was checked for blockages before fitting . PRV stopped dripping when the pressure fell to 2bar.
As long as the radiators, which all heat properly no cold spots, are operating. IE the timer is set to ON, the pressure remains fairly constant. It drops to almost zero when CH timer goes to OFF.
The usual tests which I have performed as per advise don't seem to give the expected results.
E.G.
Closing the service valves should show whether it is the boiler or pipework at fault.
Rapid rise in pressure points to expansion vessel.
I'm at a complete loss and very frustrated by all this. I feel the leak is under the floor but there is no access. I don't want to tear up carpets , laminate and flooring until I am sure.
Any ideas?
