I don't think anyone anywhere has much long term experience of condensing boilers, maybe the Scandinavians? These boilers really have only started gaining popularity here since the late 90's. I first fitted condensing boilers as part of a British Gas test project in the west central Scotland area in the early 80's while contracting to them at the time. The boilers came in from Ireland, long forgotten the make, but they used 2 seperate 40mm Mupvc waste pipes for the exhaust and intake. The layout of the boilers were kind of similar to Kestons are now. At the time no one had much of a clue about them and they were prone to going off balance if they weren't handled with care when fitting whereby an Irish guy had to jump on a plane and come and fix them! Haven't a clue how long they lasted or performed but it wasn't until the 2000's British Gas started really pushing condensing's. Things have no doubt developed a lot on condensing boilers since then. Some of the earlier boilers were probably badly designed (in an attempt to jump on the wagon) and probably did have a shorter lifespan compared to the traditional type of boiler, but they are "allegedly" better now. I've fitted them personally, usually on request from "switched on" customers or architects playing with their SAP figures, for around 4 or 5 years now and never really had any serious problems. Their lifespan now will, according to any manufacturer you speak to, be " similar or maybe only slightly less" than any other boiler type if they are correctly fitted and maintained. We will have to wait and see! 10 years? Long gone are the days of the cast iron boiler which would run for ever if properly maintained, and where the only thing to break down was a gas valve or solenoid, a thermostat or change a thermocouple. I don,t agree with the powers that be where every boiler fitted must be condensing, very few exceptions. But who are we to disagree? Mere tradesmen. People are very aware of condensing boilers and energy efficiency now from all the press coverage and stuff, but no one mentions that the slight savings in energy consumption, only around £40/year compared to a similar low water content boiler will be outweighed by increased initial costs and increased service and maintainance costs and perhaps shorter lifespan. Thats perhaps why the Government, as way of an incentive were offering £100 cash back for the customer who had one fitted and there is now the "Magic Boiler Scheme" subsidising prices to installers. Btw as yet the new regulations don't apply in Scotland, though that will change next year. In the meantime there will be some good deals to be had here this year on standard efficiency boilers as the manufacturers ofload their "dead" stock!
Tam