Radiators take over 1 hour to heat up downstairs?

It may be that the upstairs rads are stealing all the heat and the circulating water has cooled down before it reaches the downstairs rads. If you shut off all the upstairs rads and see what happens you will have discovered something. Balancing the rads might be a solution - you might also be able to speed up the circulating pump to get the water around the system a bit quicker.

http://www.miketheboilerman.com/balancing.htm

Peccavi
October 2009