In article .com,
Crewood wrote:
Thanks for th replies and the help, it seems to have worked. The cold
rads downstairs have warmed up for the first time in months.

Only thing I can't understand is why they started running cold in the
first place after working so well for years.

The pump may have lost some efficiency? Or slight blocking of the rads or
pipes? A very small change in flow can make a big difference here.

--
*On the seventh day He brewed beer *

Dave Plowman London SW
To e-mail, change noise into sound.