Bleeding radiators

[Mark359]

I have bled the radiators in my house, but one seems to suck air, instead of filler with water. Has anyone any ideas what could be wrong

 

[Burnerman]

Bleed the rad with the heating off, mate.
John

 

[Mark359]

Bleed the rad with the heating off, mate.
John

I know that one, thats why all the other radiators are free of air, just one that will not bleed through

 

[Burnerman]

So, are you absolutely sure its letting air in, then?
John

 

[Mark359]

So, are you absolutely sure its letting air in, then?
John

Yes , if you put you face to it, there is no air being pushed out. All the other radiators push air out and fill up within minutes. This one doesn't seem to be filling up.

Mark

 

[scoobydo123]

Check that the lockshield/valves are open. If thermostatic has the pin jammed?

 

[Mark359]

Check that the lockshield/valves are open. If thermostatic has the pin jammed?

Thanks, no thermostats fitted to radiators, but I will check that the valves are clear

 

[IanMichael]

is the radiator in a loft conversion? is it above the F&E tank?

 

[twgas]

do you have a sealed system? is there any pressure in it?
If it's an open system, is this problem rad the highest one on the system, if so it may be the system is not refilling.

 

[Mark359]

do you have a sealed system? is there any pressure in it?
If it's an open system, is this problem rad the highest one on the system, if so it may be the system is not refilling.

It is an open system, all the radiators upsatirs are at the same level. I agree that one is not refilling, but can't understand why. The system gets hot and works if I leave that radiator un bled, but it just doesn't get hot, obviously because the water isn't getting to it

 

[RigidRaider]

F&E tank is full?

 

[Mark359]

F&E tank is full?

the header tank has got water in. I wandered if there was some sort of blockage, but have never experienced anything like this before

 

[gordy1989]

how sludgy is the system, that might be the problem. or possibly you may have an airlock.

 

[Mark359]

how sludgy is the system, that might be the problem. or possibly you may have an airlock.

Have drained it right down and put cleaning chemical in because thought that would help, so sorry not sludgy. Unless blocked and hasn't freed it off yet

 

[expertgasman]

So, are you absolutely sure its letting air in, then?
John

Yes , if you put you face to it, there is no air being pushed out. All the other radiators push air out and fill up within minutes. This one doesn't seem to be filling up

Mark, your answer doesn't answer BM's question. Are you sure it is SUCKING air in? Or is it just not bleeding? To test, simply open nipple and spread some spit (!) around the nipple. If it is sucking, the spit will be drawn into the rad. If your spit just sits there, the orifice is blocked. In that event, it is a question of removing the nipple and pricking with a pin. But turn off both rad valves or you may have a lot of water splashing around.