Central Heating

Keston combi boiler losing over half a bar pressure daily, please help!

Anonymous user 23/02/2024 - 3.06 PM

Hello Having exhausted all the forums on this issue I am still unsure what is causing my combi boiler to lose pressure. I have had to keep topping it up every day now for the past month, I've checked the expansion vessel and all seems to be in order (topped it up a bit with a foot pump to 1 bar). I have isolated the system for 12 hours with pressure at 1.3 bar. There was no change in internal boiler pressure after this period and upon turning the return and flow valves, the pressure suddenly dropped down to 0.6 bar. I know the other main cause of pressure loss is a leak, however to be losing over half a bar on a daily basis for a month, surely this would be noticeable by now. I also live in a 4 year old block of flats so would be surprised if any wear and tear has happened to the pipes in this time. There is what's been labelled as a 'By-Pass Valve' immediately outside the boiler, could this be the culprit perhaps? Would love to get a professional in but won't be able to afford to do so until the new year. Really want to get this resolved before then as topping the boiler up daily surely can't be good for the system? Will I need to add some inhibitor if this goes on for much longer? Appreciate any help anyone has to offer, thank you in advance!