Hi all, new house with an unvented system. I have been bleeding radiators ocassionally since i moved in, just 2 that seem to accumulate air but seem to have most out the system now.
I have obviously had to top up the pressure since. The heating pressure seems to drop very slightly, but only after the hot water or CH has been on and then starts to cool down. I.e. it will sit at 1.2 bar when it is cold, goes up to 1.5 when it is running, but then goes down in very small increments to say 1.1 after having the heating on / off for a few days. I do not think it is the heating system as it does the same when i only have the hot water on too, i.e. drops ever so slightly after having it on.
There are no signs of a leak, however the PRV was opened at the home demo (I know!!!) to show me how to release pressure if it was topped up too much. There was a very small amount of water coming out the tundish, after this happened for a couple of days - and i mean residue of water not a drip. However this has now stopped and seems perfectly dry.
the only other evidence of a minor leak are at the boiler pipe on top of the boiler going up to the pump. Again this is dry, and even when the system is cold can't feel any moisture so not sure if this is a leak or just some old flux.
Sorry it is so long winded! Plumbers who installed system have said they will replace the PRV / vessel if it carries on losing pressure (if the leak out tundish returns).
Could it be air in the system causing evaporation, as i can still hear a gurgling at times from one of the radiators. It is microbore pipe.
I have obviously had to top up the pressure since. The heating pressure seems to drop very slightly, but only after the hot water or CH has been on and then starts to cool down. I.e. it will sit at 1.2 bar when it is cold, goes up to 1.5 when it is running, but then goes down in very small increments to say 1.1 after having the heating on / off for a few days. I do not think it is the heating system as it does the same when i only have the hot water on too, i.e. drops ever so slightly after having it on.
There are no signs of a leak, however the PRV was opened at the home demo (I know!!!) to show me how to release pressure if it was topped up too much. There was a very small amount of water coming out the tundish, after this happened for a couple of days - and i mean residue of water not a drip. However this has now stopped and seems perfectly dry.
the only other evidence of a minor leak are at the boiler pipe on top of the boiler going up to the pump. Again this is dry, and even when the system is cold can't feel any moisture so not sure if this is a leak or just some old flux.
Sorry it is so long winded! Plumbers who installed system have said they will replace the PRV / vessel if it carries on losing pressure (if the leak out tundish returns).
Could it be air in the system causing evaporation, as i can still hear a gurgling at times from one of the radiators. It is microbore pipe.
