Filling loop and topping up probs on Vaillant ecotec plus 837

[dicksibo]

Cannot get mains water to flow into system using filling loop. Filling loop connected, both stop valves open and only about 0.9bar in the system but mains water (plenty of mains pressure) will not flow into the system. I have uncoupled the filling loop at the stop valve (at the other end to the double check valve) and proved mains water pressure is flowing through the filling loop.

Any ideas on my next move would be greatly appreciated. I should add that the system is working OK, just want to top up the system pressure. Also I have used this filling loop to top up the system pressure on previous occasions without problem. And no I don't have a system leak, natural degradation of system/line pressure.

[mikegas]

Try it without the check valve, and replace if jammed

[Kev the gas]

is your mains pressure only .9 of a bar?

"and only about 0.9bar in the system but mains water (plenty of mains pressure)" Have you tested this with a gauge?

Is the pressure gauge on the boiler faulty?

[bill577]

press the minus button on the front of the boiler, this will give you the "electronic" pressure of the system, it will tell you if the guage is faulty ,more likely to be a stuck nrv.

[dicksibo]

If only it where that simple, the nrv is push fit and retained by a cir-clip, not a threaded connection. I've had the nrv out and checked for directional flow, it appears to be working OK. Unless any better ideas come up my next move is to remove and check the service valve that the filling loop connects to. The service valve has a bleed point fitted and when cracked open this works OK.

Looks like I've got to drain the system down, was trying to avoid that palaver.

[dicksibo]

is your mains pressure only .9 of a bar?

"and only about 0.9bar in the system but mains water (plenty of mains pressure)" Have you tested this with a gauge?

Is the pressure gauge on the boiler faulty?

0.9bar in system; mains pressure at least 2.0bar. Boiler pressure gauge appears to be OK, generally agrees with what LCD displays says when I press "i"

[bill577]

there are two taps to the filling loop, because the handles are made of plastic they some times appear to be turning but are not opening the valve, take the handles off (just a small screw in the middle )and use a spanner to open the valves.

[bill577]

you can see the valves here.

[dicksibo]

there are two taps to the filling loop, because the handles are made of plastic they some times appear to be turning but are not opening the valve, take the handles off (just a small screw in the middle )and use a spanner to open the valves.

Tried that bill577, both valves are turning thru 90degrees OK. Worth a try though

[SafeGasInstall]

faulty pressure gauge or sludge in system ! drain down to 0.0 bar ,then start filling up if then you hear water going in this will mean that if there is 2.0 bar mains pressure you have faulty/sludge pressure gauge !

make sure you open both flow and return valves under boiler

[SafeGasInstall]

when open they must been in line with pipe work ,you will need alen key or big screw diver ,make sure you do not damage them