Hi Joe and DNB, I guess you were right. The fresh air damp duct is probably
to provide fresh air to the home, not for combustion. So both the furnace
and water heater would draw air for combustion from the garage. There isn't
a closet for them. They are surrounded by walls on three sides but the one
large side is open to the garage. The garage size is about 650 SF (2 car).
Is it OK to keep the garage doors and window closed? I do have the window
near the furnace but keep it crack 2"-3" would let the rain in.

R.C.

"DN B" wrote in message
...
Joe is correct. As for the waterheater...unless its a direct vent unit,
it wont have a fresh air duct coming to it for combustion ; but, the
closet is going to need combustion air for both the water heater and
furnace burners -- there should be an opening ( a grille perhaps in the
wall/ceiling of the closet) which will let air transfer in as its being
used for combustion of these appliances. Until youre sure there is
one..crack the door at least 2-3 inches. It is national code that there
must be a source for combustion air intake otherwise, the burners will
starve for air and 'could' start to roll out of the furnace/water heater
making an unsafe situation. If in doubt, call the village inspector
and register y our concern about this, then, he will come out .