Atag, if you have the room. I've heard good things about the Broag boilers but not installed one yet. I have installed most makes from A to W and had breakdowns out of the box with all makes. In this financial climate I would look at the warranty on boilers (although some manufacturers squirm...
As with the other people check for sludge etc. Also these boilers need to have 28mm flow and return. Has the plumber checked the pump impellor is working, I had one the other day where the spindle was going around but the impellor wasn't.
This has got me confused.
I'm a member of the Chartered Institute of Plumbing and heating Engineers. Should I ask them to change their name or get a refund on my subs?
Agile you are right in the advise you've given the op.
Any RGI would of worked out the heat loss and probably found the original boiler was too big to start with.