Thanks for the reply, extremely grateful. Where would I introduce the desludging fluid? I live in a soft water area of the countryry so limescale not a problem thank God.
Thanks again for your time.
jim.

jim, January 2008

Hello Jim,
Sorry for the delay in the reply.
you can purchase fernox at any plumb center or B + Q.
You can introduce it into the system via the filling loop or radiator bleed screw using a silicon gun.
Leave it in the system for a couple of weeks and then drain down and refill.
hopefully this will sort out your problem.
Regards,
Nick

nick frost, February 2008