Been in the commercial svc. industry for 15 years, so this residential install is a little out of my scope, but i find myself with the task of replacing a boiler and hw heater next week. Removing an atmospheric 125k btu 80% boiler and putting in a 105k btu 81% with auto vent damper (5") (http://www.dunkirk.com/product_detai...&view=features )
and a standard 40Kbtu hw heater.
Chimney is brick and clay- 31.5 ft from top of boiler to cap. Chimney is inside except above roof. Location is western new york
(1) Wholesaler says that I should use a 5.5" liner. If boiler flue diameter is 6" is it ok to REDUCE the size to 5.5" ?
(2) when connecting hw Heater flue- use a why fitting or a tee fitting
(3) Is the auto vent damper a factor when sizing liner,as it will not allow the residual heat to keep the liner warm?
(4) how long will the aluminium liner last. is the cost of stainless justified for this type of installation?