rad not heating up

[goofy gorilla]

hi guys - yesterday i decided to flush out or drain my entire cental heating system, all went fine flushed out sytem, refilled with fernox rust inhibitor..filled sysytem back up again and started the boiler (vaillant ecitec 831) anyway after removing all air from system, all the radiators heat up fine except one which is downastairs next room to th batroom, that is cold, iopened the bleed vave to expel any air but none present, lockshield fully open, thermostaic valve open as well or set on 6...now the bathroom towel rad is hot the pipes going to the towel rad are hot ...the pipes leading from the towel rad to the problem rad are cold.....prior to me draining out the system all rads were working fine...i tried to balance the system by turning off most rads or leving them half open but it still doesnt heat up any ideas why...?ta

 

[AlanE]

Air is in pipe.

Close both rad valves and drain water from that radiator. Open ONE valve and bleed until bubbling stops. Close that valve and open other and bleed radiator.

Open valves and does bottom of radiator get hot? If so completely bleed rad. If bottom not getting hot close one valve and bleed and then close it and bleed with other valve opened.

Bleeding with both valves open will not normally remove air from pipes. Bleeding from each end separately normally will.

 

[Phill Peck]

Just turn off all the other rads, it will shift the air

 

[goofy gorilla]

ok will try this method first so do i turn off every rad in the house execept this problem one and then run the boiler and then see if i can bleed this rad ?...

if dont work then looks like ill have to remove or drain that problem rad and do it that way..

 

[goofy gorilla]

Just turn off all the other rads, it will shift the air

lol that worked, turned off every single rad, except one in the downstairs hall that i left open on both sides, as i thought how is the water gonna go round the system if all rads are closed both ends, ...anyway its got hot now, odd thing is no air in anywhere as i bled all rads .....opening all rads back on ...has made the problem rad less warmer, i think they may need balancing so im gonna turn down the flow on some of the rads that are not needed that much..ta

 

[Agile]

All heating systems need balancing.

You may not notice air in the system and the boiler contains an auto air vent.

Tony