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Central Heating - Help!

Posted: Sun 09 Dec 2012 9:34 pm
by PapaBravo
I have gas central heating. My radiators don't get very hot, particularly at the bottom, although the towel rails all get very hot. I think the radiators need to be bled, but I have been told that this should only be done with the boiler off!! Now I am not a heating engineer, but this does not make sense to me. In the UK I bleed rads with the boiler on full chat, so I would be grateful for advice about bleeding radiators here?

Re: Central Heating - Help!

Posted: Mon 10 Dec 2012 6:51 am
by Geoff1131
If the radiators are cold at the top you need to bleed the air from them. You say they are cold at the bottom which would suggst that there is a build up of sludge which is causing cold spots. Most boilers out here are the pressurised type which need to be kept at a working pressure of around 1 bar. This is why it is best to bleed air from the system while the boiler is off, because doing it while the boiler is on will drop the pressure and cause the boiler to stop working on its low pressure sensor.
Hope that helps.

Re: Central Heating - Help!

Posted: Mon 10 Dec 2012 7:20 am
by deputydawg
PapaBravo. Visit "Google" and search "how to bleed central heating radiators" and it will give you all you need to follow the sound advice of Geoff. If bleeding them does not work for any length of time you need to establish whether or not approx 1 bar water pressure is being maintained. If you follow the advice of how to re pressure the system and it quickly reverts to being under pressured perhaps time to get a heating engineer to service the system for you as you could have a leak in the water pipes, hopefully not under the floor of your home.

I too think the towel rails work so much more efficiently and do not understand why they are not fitted in all rooms instead of the ugly, lumpy ones. They would take up less space and look more pleasing to the eye and of course could have radiator covers on them. Best of luck with it all !

Re: Central Heating - Help!

Posted: Mon 10 Dec 2012 7:40 am
by andrew4232
yes if there hot at the top there is no air there as stated sounds like sludge in the system build of of calc etc, mr pipe does a ceantral heating system clean and de scale that my be your best option

Re: Central Heating - Help!

Posted: Mon 10 Dec 2012 8:42 am
by Jaybee
Not always sludge in the radiator as when they install systems here they just fully open both valves,instead of "balancing the system"in which case to flow through the radiator skips the bottom causeing cold spots,If this is the case you will need to balance the system to obtain equal flow rates through your rads.

Re: Central Heating - Help!

Posted: Mon 10 Dec 2012 9:00 am
by PapaBravo
Wow! Lots of good advice. Thank you very much people. PB