New boiler, rads not all heating properly.

[craigthomas75]

I have just moved into a house that i have been renovating for 12 months, i have found that some of the rads downstairs are not heating up properly. The boiler is mounted in the attic and all the upstairs rads are working fine, downstairs 2 or 3 rads are not getting very warm at all making the rooms at the front of the house (furthest from the boiler) non usable due to the fact they are too cold.
I have tried shutting all the rads off apart from the 3 problem ones and when i do this they heat up fine, once i go round turning the others back on though they simply go back to giving off barely any heat.
Any advice would be greatly appreciated.

Regards

Craig

www.nds-cards.co.uk

 

[landyandy]

Have a look here.

http://www.diydata.com/projects/centralheating/balancing/radiator_balancing.php

 

[bengasman]

if it is a white boiler, you have to make sure the pump is (still) strong enough.