I am living in an apartment in Belgium. My bedroom radiator is basically useless; it's about 1m long but only the left 10cm ever gets warm.
I have been told to bleed the radiator by opening the valve and letting the pressurized system fill the radiator with water, pushing air out until the water starts leaking out of the valve. This, however, is not working for me. I have tried leaving the valve open for weeks and nothing ever changes. I have also tried opening and closing the main radiator valve. When I close it, I hear a hiss from the bleed valve. When I open it... I also hear a hiss from the bleed valve.
I suspect that I have somehow actually worsened the problem as when I first moved here the radiator was maybe 50% operational; now it's 10%.
Is it possible that I am allowing air INTO the radiator rather than letting it escape? Is there some magic combination of "open bleed valve, open radiator, close bleed valve, close radiator" that I need to try?
I have read other DIY sites on the net but basically they say what I've already tried, or talk about turning off the central heating system which is not possible in my apartment building.
I have tried contacting the landlord but it's a monumental task to get her to take any action. That is a separate issue I'm dealing with; right now I just want to feel comfortable.
My fingers are freezing making it hard to type, so I'll wrap this up :D
I managed to get it working, but I think it's more magic than anything. A combination of turning the radiator on / off/ leaving the valve open / closed and it started working again. For the moment I simply vow not to touch it anymore!