upstairs rads are cold

[touche turtle]

Help, Aged mother in laws radiator upstairs are stone cold including the pipes leading to them. I have tried turning off downstaris rads to force hot water upstairs and there is water in the header tank in the loft, the pump is working, all the valves are open and rads are bled. The system has been drained and refilled and is heating only no hot water that is on a separate system. I am now at a loss as to what to do can anyone help please?.
Just a footnote she says the radiators worked fine for 12 years or so until one was removed and replace in an upstairs room.

System in brief :

- Basement : Boiler & pump, 1 rad
- 1st floor : 4 rads
- 2nd floor : 5 rads
- loft : small header tank

 

[Bahco]

Try bleeding the pump.

Failing that , you have an airlock and you may need to force the water through one rad at a time.

Might mean taking each feed off the rad and running it into a bucket to ensure flow. Messy job

 

[JohnD]

When you bleed the upstairs radiators, does water squirt out energetically? Is it black?

 

[touche turtle]

When you bleed the upstairs radiators, does water squirt out energetically? Is it black?

Thanks John not really a big squirt no and water is clear and very cold

 

[JohnD]

I was wondering if the water level might be below the upstairs rads, as can happen if you have a sediment blockage in the feed pipe. But is water comes out probably not. Though it should squirt if you screw the needle valve out enough.

You could try closing all the rads except one.

You probably have a motorised valve near the pump, that should completely shut off water to the cylinder and send it all to the rads, once the cylinder is hot. Could that be leaking pressure and flow to the cylinder?