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Central Heating

Radiators not fully heating

Radiators in my home are not heating properly.they are warm at top but more than half of radiator is cold rest off way down.i have took radiators out and flushed sludge out off them and I've put 1 litre of p11 system cleaner into tank. I've also put in 1 litre of system inhibitor both into small tank in attic. I put the inhibitor in 2 weeks ago. What is the problem here?

4 Answers from MyBuilder Heating Engineers

Best Answer


Adding the cleaner to the tank isnt always the most effective way of getting into the system. Some systems have the same water sat in the tank with very little movement during on/off times. I would recommend isolating a rad or draining the system and adding the system cleaner there. Allow to circulate for a week or 2 before draining and possibly flushing problem rads again, then add inhibitor via the same point. Also to back up Heat Centrals answer a magnetic filter fitted at the return to the boiler will help to catch any remaining suspended sludge which is circulating (this will not remove solid sludge which has had time to settle) If you are able to cure the problem there is a good chance that a filter will help to prevent it from happening again any time soon.



Answered 28th Jan 2015

Imagine they are still sludged up, you will keep spending money until you replace rads and fit a magnaclean.


Answered 28th Jan 2015

Hi. If system was very dirty then you may need to clean/replace circulation pump.


Answered 28th Jan 2015

It does sound like the radiators have a build up of sludge, its just requires a flush or magnaclean running, tap the radiators at the bottom to loosen it up, a flush or magnaclean will take this out of the system, it makes a lot of difference to the efficiency of your heating system.


Answered 30th Jan 2015

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