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Central Heating Question
Banging / scraping noises in central heating
Since starting the central heating this year, I've started hearing noise (banging/ scraping) after about 15-20 minutes which sounded as though something was about to explode, so I turned it off. Tried this a couple more times with the same result, then thought it might be air in the pipes (the bedroom radiator needs bleeding every couple of weeks during the winter), so I bled the bedroom and bathroom radiators, which allowed me to run the heating for about three hours before the noise started up again.
The radiators felt a lot hotter than normal when the system was running – I had wondered if the guy who came to do the gas check a few months ago might have adjusted something (the heating hadn't been on since then and I don't tend to have the hot water on since the shower and washing machine both heat their own). I got down under the gas fire and found the boiler thermostat had been turned up to max, which it hasn't been since I've been there, so I turned that back down and tried the heating again last night – it ran OK for about an hour, then the radiators were overheating again so I switched off before any noise started.
The noise seems to be in the pipes around the pump (which is new so I don't think that's the problem unless it hasn't been installed properly) – I'm suspecting something's clogged/scaled up and it's causing the overheating, but that's just my guess.
To be fair if you have an old back boiler it is very likely that it is blocked within the pipework? If could even be the pump not circulating correctly. That said again if its not circulating then your back to the same problem..my opinion is that you need a professional heating engineer to attend to have a good look around as its not a DIY job.. Hope that helps..
Answered 7th Jul 2014
as above, not a diy job. have the pump replaced, power flush system then refill, problem solved.
Answered 23rd Dec 2014