M
mystifiedboilerowner
Hi everyone,
I have a HomeServe contract so am covered for engineers looking at my boiler and central heating, but I suspect the issue I'm having is going to be tricky to diagnose, so I thought I'd just ask here in case anyone's answer might be able to point me and the engineers in the right direction.
I have a twelve-year-old Ideal Isar HE24 (yes, I know what you're all thinking, but I am at least covered every time it breaks down).
The issue I am having just now is that the system will sometimes suddenly lose a little of its pressure, but then carry on as normal without any further pressure loss.
To be clear, this is not the steady, gradual drop in pressure that I assume (please correct me if I'm wrong) most people would see with a typical leak. When completely cold, my boiler is usually topped up to around 1 bar or a little more, but on two occasions recently, over a period of a few hours, the pressure when cold quickly dropped to 0.75 bar and then just stayed there with no further drop of pressure occurring.
For example, immediately after one such drop, I topped up the system to about 1.1 bar on 7th August, continued to use it as normal for heating and hot water, and found the 1.1 at cold was maintained solidly until 17th August when there was a sudden drop of the pressure when cold to 0.75 bar. It is now 21st August and there has been no further drop of pressure, which remains at 0.75 bar when cold - I am keeping it there for now rather than topping up further in case I can see any further drops in pressure over the coming days.
I have found no connection between heating being on or off and these pressure drops, nor to hot water use and pressure dropping (not that there would be any). The only thing that seemed to happen on two occasions recently when I suddenly lost a little pressure was that there was a spell of cold weather. I did not use the heating any more than usual on either occasion as a result of the cold snap, so I think this is likely just a coincidence, particularly as I have been running the heating and the boiler has pretty much got to full temperature every morning since the last drop on Friday, with no further loss of pressure resulting from this use of the heating every morning. The drops in pressure do seem to present as single, isolated events, and between the occurrence of these pressure drops, everything seems to be working normally.
I have had both the expansion vessel and the PRV replaced recently as the pressure was climbing to 3 bar when the heating was on and water was coming out of the relief valve. This issue is now solved and the pressure when hot is within normal range (about 1.75 bar) - but I still get these intermittent sudden decreases in pressure. I can't see any evidence of a leak around radiator valves, but something like this probably wouldn't be visible. If there's a leak under the floorboards, accessing pipework shouldn't be too difficult - crawlspace under ground floor and upstairs floorboards should come up without too much difficulty - but I'm keen not to do this if the results are going to be inconclusive, which is likely given the intermittent nature of this issue.
Any thoughts would be very much appreciated.
I have a HomeServe contract so am covered for engineers looking at my boiler and central heating, but I suspect the issue I'm having is going to be tricky to diagnose, so I thought I'd just ask here in case anyone's answer might be able to point me and the engineers in the right direction.
I have a twelve-year-old Ideal Isar HE24 (yes, I know what you're all thinking, but I am at least covered every time it breaks down).
The issue I am having just now is that the system will sometimes suddenly lose a little of its pressure, but then carry on as normal without any further pressure loss.
To be clear, this is not the steady, gradual drop in pressure that I assume (please correct me if I'm wrong) most people would see with a typical leak. When completely cold, my boiler is usually topped up to around 1 bar or a little more, but on two occasions recently, over a period of a few hours, the pressure when cold quickly dropped to 0.75 bar and then just stayed there with no further drop of pressure occurring.
For example, immediately after one such drop, I topped up the system to about 1.1 bar on 7th August, continued to use it as normal for heating and hot water, and found the 1.1 at cold was maintained solidly until 17th August when there was a sudden drop of the pressure when cold to 0.75 bar. It is now 21st August and there has been no further drop of pressure, which remains at 0.75 bar when cold - I am keeping it there for now rather than topping up further in case I can see any further drops in pressure over the coming days.
I have found no connection between heating being on or off and these pressure drops, nor to hot water use and pressure dropping (not that there would be any). The only thing that seemed to happen on two occasions recently when I suddenly lost a little pressure was that there was a spell of cold weather. I did not use the heating any more than usual on either occasion as a result of the cold snap, so I think this is likely just a coincidence, particularly as I have been running the heating and the boiler has pretty much got to full temperature every morning since the last drop on Friday, with no further loss of pressure resulting from this use of the heating every morning. The drops in pressure do seem to present as single, isolated events, and between the occurrence of these pressure drops, everything seems to be working normally.
I have had both the expansion vessel and the PRV replaced recently as the pressure was climbing to 3 bar when the heating was on and water was coming out of the relief valve. This issue is now solved and the pressure when hot is within normal range (about 1.75 bar) - but I still get these intermittent sudden decreases in pressure. I can't see any evidence of a leak around radiator valves, but something like this probably wouldn't be visible. If there's a leak under the floorboards, accessing pipework shouldn't be too difficult - crawlspace under ground floor and upstairs floorboards should come up without too much difficulty - but I'm keen not to do this if the results are going to be inconclusive, which is likely given the intermittent nature of this issue.
Any thoughts would be very much appreciated.
