Hi everyone
I registered here for some advice, as after reading many threads about slow pressure loss on combi boilers, none seem to be quite the same as what I'm experiencing and would just like to help narrow things down before I call an engineer out.
I have a Biasi M90D.24s Its fairly new I believe but was in the house when I moved in 18months ago.
Ominously the filling loop was in place when we moved in, which implies a known problem. The boiler pressure was at zero, so I filled it and everything worked fine. no problems with hot water or heating for all this time.
however the pressure does seem to fall slowly over time, I need to keep a closer eye on what conditions this happens, but it lost pressure last summer without any use of the heating.
Now the obvious thing would be a leak, its difficult to check the whole house as some pipes are under boards which are also under stone tiles, but I'm fairly sure I've no leaks on the heating circuit.
This seems backed up by the fact that despite having recharged the heating maybe 4-5 times in the last 6 months (not full loss of pressure, just a top up) I never find any air in the rad's when I bleed them.
Now the curious bit, the hotwater tap in the bathroom is a cheap one and is probably getting to the point where I need to change the washer as its sometimes tricky to turn off without a drip. Only when the heating is on I can hear air passing through this tap, and the hot water arrives at it suspiciously quickly after the heating has been on recently, followed by a cold period and then hot again.
Can anyone explain this, and is the pressure loss related, or is it more likely I have two different issues?
I wondered if the bypass valve was somehow letting water circulate the DHW circuit just a little when the heating is on?
Could there be a leak in the hotwater heat exchanger allowing CHW to escape into the DHW?
Can the diverter valves allow a little to go each way?
Any guidance would be appreciated.
Thanks
Ben
I registered here for some advice, as after reading many threads about slow pressure loss on combi boilers, none seem to be quite the same as what I'm experiencing and would just like to help narrow things down before I call an engineer out.
I have a Biasi M90D.24s Its fairly new I believe but was in the house when I moved in 18months ago.
Ominously the filling loop was in place when we moved in, which implies a known problem. The boiler pressure was at zero, so I filled it and everything worked fine. no problems with hot water or heating for all this time.
however the pressure does seem to fall slowly over time, I need to keep a closer eye on what conditions this happens, but it lost pressure last summer without any use of the heating.
Now the obvious thing would be a leak, its difficult to check the whole house as some pipes are under boards which are also under stone tiles, but I'm fairly sure I've no leaks on the heating circuit.
This seems backed up by the fact that despite having recharged the heating maybe 4-5 times in the last 6 months (not full loss of pressure, just a top up) I never find any air in the rad's when I bleed them.
Now the curious bit, the hotwater tap in the bathroom is a cheap one and is probably getting to the point where I need to change the washer as its sometimes tricky to turn off without a drip. Only when the heating is on I can hear air passing through this tap, and the hot water arrives at it suspiciously quickly after the heating has been on recently, followed by a cold period and then hot again.
Can anyone explain this, and is the pressure loss related, or is it more likely I have two different issues?
I wondered if the bypass valve was somehow letting water circulate the DHW circuit just a little when the heating is on?
Could there be a leak in the hotwater heat exchanger allowing CHW to escape into the DHW?
Can the diverter valves allow a little to go each way?
Any guidance would be appreciated.
Thanks
Ben