Hello everyone, its been a long time since I posted. My question is about hot-water heater closet. I have not put on a door yet and I'm curious about combustion air. If using a louvered door would you still need outside air brought in? The draw through the pipe seems to be taking place put I occasionally get gas smells. My first thought is will the door stop the smell or is it just a try and see. Thanks for any input, Sam

If you're getting gas or gas-exhuast smells in that area it's highly likely that the heater is backdrafting under some circumstances (maybe when the bathroom fan or clothes dryer or furnace/boiler is running, depressurizing the house?) If so, this is a serious health hazard and needs attending to! The "best" solution to this type of issue is to use only sealed combustion forced-draft hw heaters/boilers, with electronic ignitoin (no standing pilots) but that can be quite expensive. Otherwise, figure out the circumstances under which backdrafting occurs and see if it can't be rectified. If the flue for the HW heater is very short, sometimes a taller stack can be sufficient to overcome the backdrafting pressure, but don't count on it.

Thanks for the info, it does bring to mind a question though.  The dryer is in the laundry room with the hot water heater and the room is pretty tight so backdraft is a real possibility. Carbon monoxide is odorless, what am I smelling.
Thanks, Sam

Sammy,

You are probably smelling the Mercaptan that is added to odorless natural gas.