My boiler has just been condemmed as the flue which goes into a small lightwell is no longer allowed. I need to change my boiler anyway from a regular combi to, I guess, a condensing one (from what I've read) for a 1 bedroom flat. My main concern is what to do about the flue - it will need to reach up to the roof which is 3 floors away. Is this possible and is it true that some boilers can use regular plastic piping as flues? (or it seems that I'll be paying around £40 per metre for extension pieces). Any suggestions or advice on the best boiler and flue to get would be greatly appreciated. Thanks.