Bleeding the system

[VinceB]

Can anyone help with bleeding my central heating sytem please.

The header tank ran dry (ball-cock problem) and air got in the sytem.

I know from past experience (after fitting a new rad) that the system will not self-bleed.

It's a two storey house, gas boiler, pump is working, hot water and downstairs rads are fine.

I have a drain-valve on a downstairs rad and I have forced air out of the sytem by attaching a hose from the cold water tap and running water throught the sytem whilst putting my finger over the outlet hole in the header tank to force water into the cold water tank. This method worked before.

I've made some progress after about four sessions - the upstairs rads are just warm - but clearly there is still air in the syatem. All rads have been bled and are full.

Any advice appreciated - is it best to have the heating on or off when flushing - should the rads be open or closed?

Many thanks

 

[Boilerman2]

Why don't you just go round each rad in turn and vent off using a radiator bleeding key (see Michael Mcintyre for details)

 

[VinceB]

Boilerman2

I've bled them all dozens of times - before I flush, I always bleed every rad.

Any other suggestions?

Thanks
VinceB

 

[seco services]

have you tried turning the hot rads off temporarily and turn the pump speed up.
and only heating being called for.

 

[VinceB]

Seco Services,

Yes I have - the pump is on max setting.

When I'm trying to flush the air out of the system, is it best to have the heationg on or off?

Thanks
VinceB

 

[45yearsagasman]

System should be off and any zone/diverter valves sould be put to manual position using lever on side of valve.