i'm looking for a boiler that will last longer than 15 years. i know the cast iron boilers are good for 30 years but i'm looking for a boiler that is stainless steel and will have very good efficiency. the boiler i have now does my superstore stainless water tank that has a lifetime warranty. so this boiler has to do my hot water and a basement zone. the existing boiler is a dunkirk Q90. it's lighting very hard. the tech for dunkirk says that the boiler needs to have it's last rights. the sent in their best tech to look it over and he tuned it to factory specs. it's natural gas. and the block is aluminum. it's been a great boiler and i only had to do a inducer fan and a igniter. the boiler is a three pass pin boiler. i put this in when i moved into this house in 2000. i cleaned it out 2 years ago for the first time and it was very clean. it has been lighting hard ever since. i had a call into the company and the techs said to me (this boiler is still running?) i said yes but it's lighting hard it rattles the pvc pipe so it sounds like its going to come thru the floor in the livingroom sometimes. about 75% of the time it lights off well. the company said to me that they didn't have one in their lab last more than 15 years. i think because i use the wood stove for heat in the main house that it saved some life for the boiler. so i'm on borrowed time here. i wire and understand all the residential boiler out there. including the computerized systems. i troubleshoot them. when the plumber or oil burner company can't get one going they call me. so i know boilers pretty well. so the boilers that i have been wiring are wall hung or floor standing but most of them are the same boiler inside. i'm looking for a boiler that is not cast iron because they don't have the efficiency and it takes some time to heat up the cast iron so between both it burns more gas. the one that i have now goes from 50 degree water to throwing heat in the baseboards in 4 minutes. the newer wall hung boilers are quicker. anybody have any good experiences with theirs? and the other problem is that the average price to put in one of these wall hung boilers goes from 12,000 to 20,000 dollars.