Cold section in Radiator scenario - what action to take

[sjguk]

Dear forum,

I know this is a very comon question, i have scoured other posts but not come across one which has been described exactly as mine.
I am really inexperienced with radiators, and before i pay for a plumber to come out i thought i'd give it a shot ans see if anyone can confirm my problem.

Moved into new house and have only just tryed out the central heating. Its a Combi boiler - Alpha 280 i think(about 10 years old). There are 5 radiatiors in the house - all work fine apart from lounge - this radiator only heats up at the top. The temperature at the top is not that hot though. The pipework leading into the Rad is very hot, its hot even past the entry valve. Ive noticed thought that the return pipe is always cold. I have turned both valves at either side of the rad on full.
I have tried to bleed the system, when opening the bleed valve, some air was released - followed by water trickling out of the input valve(temp control knob). Still only mild heat at the top of the Rad.
This morning when i came down, i was greeted with a puddle of water from the problem rad and the water pressure had dropped just above 0 on the boiler.....

Sorry for the lengthy description but hopefully someone can pinpoint my prob?

Thanks for any input
Stuart

 

[corgiman]

you must top up the system and bleed it properly

do you know what boiler you have, a name would be usefull

 

[JonB]

Corgi
Its an Alpha 280

 

[corgiman]

i think they have an integral filling loop

do u have the intsructions at all it will tell you there