I have moved into a newly built house in October.
When I open the windows I get fumes odor in certain areas /packets of the first floor of the house. There is no odor on the 2nd floor or the basement, where both the gas water heater and furnace are located.
It does not smell like rotten eggs, and does not smell like gas from the stove or fireplace before igniting. It is more faint, with non-discript odor. My wife describes it as "ozone smell".
There is no odor when the windows are closed.
I have sort of ruled out the furnace because I had it completely off but was still getting the odor. If it's the gas water heater, than what may be the cause?
We already had the builder move the air intake for the furnace, to try to remedy the problem, but it did not make a difference.
Currently the intake and exhaust come out on the side of the house via PVC pipes.
I'd be glad to post some pics of the water heater setup tonight.
Your help is much appreciated.