Was on a call yesterday for a water heater changeout and the homeowner asks me to change the filter a quick look in the attic and there is a 2 year old 80% forced air funace sidewall vented with b-vent out the side of the home and terminated.i did not see a power venter on it either and told the owner it didnt seem right.question is i have installed 82% boilers that can be sidewall vented which are draft induced wondering why you cant with forced air.