Am afraid this might be a long description!
We have a sealed pressurised central heating system, with an unvented hot water cylinder, with a Glowworm 30sxi condensing boiler. We've always had a bit of trouble with the radiator in our lounge not getting very warm. Previously the problem has been due to a build up of sludge, which was cleared out 2 years ago and all worked fine. But last winter that rad was getting cooler again, and our bedroom rad wasn't working well either. So this year, in advance of autumn, I thought I would try and get them checked and working properly. We had a local plumber round, they drained the system, and ran cleaner through it - no difference. So they said it needed power flushing, so they came and ran some sort of flush for a couple of hours, and we ended up with a system that was far worse than when we started - now we had 5 rads not working. They didn't know what else to do and haven't come back to me.
So we decided to get the system properly power flushed, at some expense. After flushing it nearly all day, we were left with a system that was working, and, hurrah, the lounge rad was lovely and hot. All was good, except a week later it went cold again, and so did the next one on the run, and now actually there's not much heat upstairs either. The powerflush people said the lack of heat wasn't likely to be anything in the pipes and could be sticky TRVs, so we have changed them on the rads in question to just straight valves - which hasn't made any difference.
But I have also noticed that the boiler is coming on for about 2 minutes, and then cycling (pump and/or fan seems to be going but no heat being created) for 3-5 mins, and then coming on again for 2 mins, and then cycling, etc, etc. So the heat is not really getting round the system now in anycase, just the first few radiators.
Does anyone think it's an airlock? If it is an airlock, why did it happen after a week? Or could it be a problem with the boiler? What I cannot fathom is how the system was working fine for a week, and now isn't and I hardly have any heat, so something must have happened.
Any ideas, gratefully received!!
We have a sealed pressurised central heating system, with an unvented hot water cylinder, with a Glowworm 30sxi condensing boiler. We've always had a bit of trouble with the radiator in our lounge not getting very warm. Previously the problem has been due to a build up of sludge, which was cleared out 2 years ago and all worked fine. But last winter that rad was getting cooler again, and our bedroom rad wasn't working well either. So this year, in advance of autumn, I thought I would try and get them checked and working properly. We had a local plumber round, they drained the system, and ran cleaner through it - no difference. So they said it needed power flushing, so they came and ran some sort of flush for a couple of hours, and we ended up with a system that was far worse than when we started - now we had 5 rads not working. They didn't know what else to do and haven't come back to me.
So we decided to get the system properly power flushed, at some expense. After flushing it nearly all day, we were left with a system that was working, and, hurrah, the lounge rad was lovely and hot. All was good, except a week later it went cold again, and so did the next one on the run, and now actually there's not much heat upstairs either. The powerflush people said the lack of heat wasn't likely to be anything in the pipes and could be sticky TRVs, so we have changed them on the rads in question to just straight valves - which hasn't made any difference.
But I have also noticed that the boiler is coming on for about 2 minutes, and then cycling (pump and/or fan seems to be going but no heat being created) for 3-5 mins, and then coming on again for 2 mins, and then cycling, etc, etc. So the heat is not really getting round the system now in anycase, just the first few radiators.
Does anyone think it's an airlock? If it is an airlock, why did it happen after a week? Or could it be a problem with the boiler? What I cannot fathom is how the system was working fine for a week, and now isn't and I hardly have any heat, so something must have happened.
Any ideas, gratefully received!!
