Cold and Noisy radiators?

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