In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
History: hot water boiler being used to heat bath house. 500 mbtu. Has history of spill switch tripping. There is a duct that is supposedly connected to outside to bring in air. Owner hires someone to add fan to duct in order to increase air. Next day CO alarms start ringing. Spill switch does not trip. Owner hires different plumber who tests flue and finds 1100 ppm. Plumber cleans flue passage ways in between boiler sections. Flue CO goes down to mid 200s. Flue temp is 115. No CO in room. This morning I am there and CO alarm goes off. Ran home and get personal tester and there are 90 ppm in room. Shut boiler down. I am in middle of combustion training. Ideally we should get someone fully qualified to look over system BUT we are in hurricane sandy area and no one is around(in general there are not many qualified and reliable gas combustion people in this area). What is the next step. I can get my hands on combustion testers but I would need some guidance from the folks on the wall. Why would bring in more fresh air result in higher CO levels? Is it possible that the fan is pressurizing the flue and preventing the flue gases from entering the flue? is there too much cold air coming in which is lowering flue temps?