G'day, all.
A good friend and client of mine has a Vokera Excell combi. It has been fine until the last few weeks when it has been losing most of the system pressure over a day or 2. She keeps topping up and the engineer her domestic emergency insurance sent was only there for 5 minutes and said there must be a leak in the heating pipework.
This may well be the case. Investigating for such a leak will be a pain in the ass - it's all on the ground floor so no leak will show up downstairs!
I went to have a look and noticed that the expansion vessel had no air charge, so after sorting that it was better but still losing system pressure. The first night it was nearly down to 0 in the morning, the second night it was ok, the third down to 0.5 bar. At no point have I or the client observed any water discharging from the PRV outlet.
It might be a heat sensitive leak in the pipes, but before I lift boards (or mess with the boiler flow / return ball valves which might start to leak), is there any way there could be a leak from the system side of the boiler into the hot water outlet via the secondary heat exchanger? If it was leaking from the cold mains in, then one would expect the pressure to rise, not fall, but if it only leaks as the divertor valve switches over to HW from CH and there is a leak into the HW side then it could theoretically lost the pressure this way.
Am I speculating wildly or is this a known fault?
A good friend and client of mine has a Vokera Excell combi. It has been fine until the last few weeks when it has been losing most of the system pressure over a day or 2. She keeps topping up and the engineer her domestic emergency insurance sent was only there for 5 minutes and said there must be a leak in the heating pipework.
This may well be the case. Investigating for such a leak will be a pain in the ass - it's all on the ground floor so no leak will show up downstairs!
I went to have a look and noticed that the expansion vessel had no air charge, so after sorting that it was better but still losing system pressure. The first night it was nearly down to 0 in the morning, the second night it was ok, the third down to 0.5 bar. At no point have I or the client observed any water discharging from the PRV outlet.
It might be a heat sensitive leak in the pipes, but before I lift boards (or mess with the boiler flow / return ball valves which might start to leak), is there any way there could be a leak from the system side of the boiler into the hot water outlet via the secondary heat exchanger? If it was leaking from the cold mains in, then one would expect the pressure to rise, not fall, but if it only leaks as the divertor valve switches over to HW from CH and there is a leak into the HW side then it could theoretically lost the pressure this way.
Am I speculating wildly or is this a known fault?