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Central Heating

1 rad that doesn't get hot, it only gets slightly warm could this by an air lock?

combi boiler system valiant eco plus
i think i have an air lock in my system, the whole system works fine except for 1 rad that doesn't get hot it only gets slightly warm, could this be an airlock and if so what is the best way to move it, the hot water works fine.

2 Answers from MyBuilder Heating Engineers

Best Answer

if the rad is warm at the top and bottom the other rads could need regulating, try turning other rads completely off and see if it gets warm then, and bleed them of course before you turn them off! if it gets warm go back to the rads you closed and open them one full turn only and see if that sorts problem if not could be diverter valve issues too! or weak pump or blockage even causing restriction!

If it is an air lock you need to turn all rads off apart from the one thats not working and bleed it with one valve closed for a while and then with the other valve closed for a while to remove air lock, but dont forget you have to top combi boiler back up if water stops coming out of vent.and try running boiler with that rad on only this usualy sorts problem!

kind regards



Answered 19th Dec 2012

agree with the above however if this doesn't work and this particular radiator has been switched off for an extended period by the Thermostatic Radiator Valve (big one with numbers on) it could have potentially seized. take the top off (you can do this with no tools) and tap the exposed pin which should release it. If none of the above works i would recommend getting professional assistance


Answered 22nd Jan 2013

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