Currently, I have an ice cold radiator in the bedroom above the kitchen where the boiler sits and one downstairs immediatly - next door to the kitchen - so both closest to the boiler.
I've bled both radiators and no joy :-(

All the other other radiators work well.

Also all make a noticeable hissing noise especially the one that doesn't work in the bedroom above the boiler.

I'm guessing I need a new bolier as that makes a racket too, but If i can avoid that cost that would be great.

Alan, December 2004

Hi, I have just been having the same sort of problem...It is proberly sludged up,
drain some water off, then Use Sentinal x400. £12.99 at Homebase, follow the instructions about how long to leave this in......I left mine in for about 3-4 weeks, then drain off completely and re-fill and add Sentenal x100 £12.99 at Homebase.
Sounds (hisses, bangs, plops.) have completely gone and the rads are giving more heat.
Hope this helps.....Details given to me by a Brit. Gas engineer.

Davey, January 2005