P
Prof Yaffle
Looking for some help here - not my boiler, so consider me a proxy. I'm also by no means a heating engineer: I'm just looking for pointers, as the owner of this boiler is now caught firmly between "not us", "not us" and "not us" - nobody will take responsibility, and just calls into question everybody else's work. Where next, what else can we test to definitively find the fault?
~5+ year old Ideal combi boiler, under warranty, regularly serviced. Losing pressure over hours to days - mostly overnight, when cold. Has been doing this for ~3 months; boiler has never been 100% reliable, and would sometimes "die" if left unattended for a couple of weeks, especially in cold weather (no further details on the nature of this, merely that it couldn't be relied upon to e.g. keep frost at bay).
PRV has been changed. Heat exchanger has been changed. Demand valve has been changed.
Isolation test: Boiler has been isolated and repressurised. Still loses pressure.
Heating has been isolated and pressure tested, and also tracer gas used - no leaks found. Thermal imaging shows no leaks. Reopening system showed tracer gas coming out of boiler flue.
On occasions, pressure appears to increase for a period before dropping back. This is likely to be when the heating is on, though, so may be "normal".
No signs of any water egress anywhere (and this has been going on for months, so there's a good chunk of water missing). No water coming out of the external pipework (plastic bag over the end, dry). No plasterboard damage. No corrosion. No wet grout where pipes go through screed in kitchen. No signs of damp around or below the boiler.
Thoughts? What can it be except the boiler, given the isolation test? And, if not the PRV or heat exchanger, what else? Expansion vessel? Dodgy pump, perhaps sticking and causing the PRV to vent? Fairy folk? Given the repeated refilling of the system, and the lack of any water damage, I'd have assume that the water is evaporating, which still points a finger at the heat exchanger, but I'm at the end of my knowledge now.
Genuine thanks in advance for any thoughts, as this is causing significant grief for an elderly couple...
~5+ year old Ideal combi boiler, under warranty, regularly serviced. Losing pressure over hours to days - mostly overnight, when cold. Has been doing this for ~3 months; boiler has never been 100% reliable, and would sometimes "die" if left unattended for a couple of weeks, especially in cold weather (no further details on the nature of this, merely that it couldn't be relied upon to e.g. keep frost at bay).
PRV has been changed. Heat exchanger has been changed. Demand valve has been changed.
Isolation test: Boiler has been isolated and repressurised. Still loses pressure.
Heating has been isolated and pressure tested, and also tracer gas used - no leaks found. Thermal imaging shows no leaks. Reopening system showed tracer gas coming out of boiler flue.
On occasions, pressure appears to increase for a period before dropping back. This is likely to be when the heating is on, though, so may be "normal".
No signs of any water egress anywhere (and this has been going on for months, so there's a good chunk of water missing). No water coming out of the external pipework (plastic bag over the end, dry). No plasterboard damage. No corrosion. No wet grout where pipes go through screed in kitchen. No signs of damp around or below the boiler.
Thoughts? What can it be except the boiler, given the isolation test? And, if not the PRV or heat exchanger, what else? Expansion vessel? Dodgy pump, perhaps sticking and causing the PRV to vent? Fairy folk? Given the repeated refilling of the system, and the lack of any water damage, I'd have assume that the water is evaporating, which still points a finger at the heat exchanger, but I'm at the end of my knowledge now.
Genuine thanks in advance for any thoughts, as this is causing significant grief for an elderly couple...
