Help needed - Rads hot downstair and only partially upstairs

[Wahook]

My system was drained today so that a rusty leaking rad can be removed and replaced with new one. When the system was re-filled, a part of the house upstairs the rads are not getting hot at all. But every other rads are working fine. The rad that was replaced is actually in the part of the house that the rads does'nt work.

Obviously it's not the pump? Right? All rads were bleed and air removed before turning the system back on. Water flows freely (but cold only).
It's driving me mad coz in changing a rusty rad that was working fine has now caused 3 other rads not to function.

Is balancing a option?

 

[John506]

Yes balancing is an option.

It could may well be the pump.

Shut off all the rads off besides 1 cold one, let the water run through a bit, then turn this 1 off, and open another cold rad. Do these in turn. Bleed these for air whilst doing them.

 

[jameshunt]

could be an airlock - but OP if you say water comes out of rad when you bleed it then this seems v strange. did you vent the pump? doing as John says is your best bet and will probably shift any air blockage in the pipework, which can then be vented from the individual rads. Turn off only the TRVs/manual radiator valves (not the lockshield) and try it... then vent again after with the pump OFF.

 

[Wahook]

cheez everyone, your tips certainly help. Still not 100% hot like it was before. Anyway, like you said, I turned off all the rads and open one at a time and it did the trick! How much money have you saved me from hiring an expert? But the some rads (especially x2 column rads) does'nt get burning hot like others. That probably means I will still need british gas to change the pump???