Thank you for your suggestions folks, very useful.
Thanks also for the suggestion re PCBs, we have had numerous however the boiler just fries them to a cinder every few months (during winter) and Potterton have been unable to do anything to stop it (we are told the other Suprimas had a...
We have come to the end of our tether with our useless 5 year old Potterton Suprima 120 boiler and are fed up with being COLD!!!
Can anyone recommend a reliable boiler (not a combi), it needs to be for an open vented system (I think) for a 4-bed detached oldish house.
Any recommendations...