radiator hot at bottom but doesn't bleed

[lmhud]

The radiator hot at bottom but cold at the top, when I undo bleed screw no air comes out.

Any ideas.

Thanks

 

[CBW]

What does come out?

 

[lmhud]

What does come out?

Nothing.

 

[CBW]

What type of system do you have?

 

[lmhud]

What type of system do you have?

I don’t know ? It’s not a combination boiler, we have a hot water tank upstairs.
Does that help?

 

[CBW]

Sort of. Is there anywhere you need to add pressure?

 

[lmhud]

No. Boiler has no options for adding. It’s a Veissman

 

[JohnD]

is it a 100 Vitodens Compact? With no pressure gauge? And are the radiators relatively old? and is there a small (1ft x 1ft x 2ft) water tank in the loft, with a ball float like in a traditional WC cistern? How deep is the water in it? How deep is the layer of mud?

 

[JimCrow]

If the system is full then maybe the air bleeder is blocked, remove bleeder and push a pin or thin wire in to clear it.

 

[lmhud]

is it a 100 Vitodens Compact? With no pressure gauge? And are the radiators relatively old? and is there a small (1ft x 1ft x 2ft) water tank in the loft, with a ball float like in a traditional WC cistern? How deep is the water in it? How deep is the layer of mud?

Have to check that tomorrow, it’s in not easy to get to. Thanks

 

[lmhud]

If the system is full then maybe the air bleeder is blocked, remove bleeder and push a pin or thin wire in to clear it.

I have removed the whole nut and nothing happens, no air escapes.

 

[Elkato531]

If there is water in the expansion tank then you probably have a blocked cold feed meaning that water can't get into the heating system. Usually the problem is sorted by chopping out and replacing the cold feed/vent connection.

 

[winston1]

I have removed the whole nut and nothing happens, no air escapes.

What about your pin as suggested?

 

[terryplumb]

Have you checked the water level in the small f&e tank ,(probably in the loft )?