Bleeding radiators, air releasing but not water???

[neyleopc]

Hi, I've had air in some of my radiators (well most!) so I've been bleeding the air our of them but on a couple of radiators (upstairs) I've had lots of air coming out but then the air stops hissing and I don't get any water squirting out that you normally would do. Also the heater is heating up better but the top of the radiator remains cold?

Any advise would be welcome!

 

[gas4you]

If it is a conventional open vent system check your small header tank in the loft is full of water. If it is you will have a blockage in the cold feed from the header tank where it t's into the rest of the pipework.

If its a combi or system boiler you need to repressurise your system with water before continuing to bleed rads.

 

[pannierstan]

Have you turned the system off while you are doing this and where are these two radiators?

Stan

 

[neyleopc]

Both radiators are upstairs (bathroom and a bedroom). I've tried bleeding with boiler off and then again when on! I know I shouldn't have when on! The boiler pressure is sometimes struggling with low pressure, so perhaps it's this!

 

[gas4you]

pressurise to 1.5 bar then try bleeding out rads.