Hello
I've just moved into a new house with a Grant 90 Combi Mk2. Noticed there was some pressure loss over a day or two, maybe 0.2-0.4 bar, so topped up and bled radiators. No losses anywhere else in system, or at least that I can find. Still gradual loss continued.
When we started using the heating for an hour an evening, we were having massive pressure build up then losing pressure rapidly after timed heating shut off - complete loss every time to 0 bar.
After exploring various avenues, found out the Expansion Vessel was full of water, so replaced this. This controlled the pressure build up and now never goes above 2 bar. However, still same problem with pressure loss. So replaced the Grant 2.5 Bar Internal Pressure Relief Valve (MPCBS28). Old one was very grimy inside. But still get pressure loss to 0 bar - the outside pipe has a steady drip from it. Water from overflow looks clean, but lots of oil staining around area, think from flue pipe vent. Even without heating on, we lose pressure, entire 1-1.2 bar per day and overnight.
So, what should I do next? Is this new PRV a dud so should I replace it or is there something else causing an issue?
Many thanks in advance for your help.
Richard
I've just moved into a new house with a Grant 90 Combi Mk2. Noticed there was some pressure loss over a day or two, maybe 0.2-0.4 bar, so topped up and bled radiators. No losses anywhere else in system, or at least that I can find. Still gradual loss continued.
When we started using the heating for an hour an evening, we were having massive pressure build up then losing pressure rapidly after timed heating shut off - complete loss every time to 0 bar.
After exploring various avenues, found out the Expansion Vessel was full of water, so replaced this. This controlled the pressure build up and now never goes above 2 bar. However, still same problem with pressure loss. So replaced the Grant 2.5 Bar Internal Pressure Relief Valve (MPCBS28). Old one was very grimy inside. But still get pressure loss to 0 bar - the outside pipe has a steady drip from it. Water from overflow looks clean, but lots of oil staining around area, think from flue pipe vent. Even without heating on, we lose pressure, entire 1-1.2 bar per day and overnight.
So, what should I do next? Is this new PRV a dud so should I replace it or is there something else causing an issue?
Many thanks in advance for your help.
Richard