Restaurant Guy wrote:
We've had an oil smell coming through our vents for about a year. Our
local heating service company has come out twice and found nothing.
Neither the smoke detectors nor the carbon monoxide detector protest
and we haven't had any apparent health effets. Yesterday I realized
that the smell only comes through only after the temperature exceeds
the setting on the thermostat and contines for a while until the fan
stops blowing. I don't know if it works this way but I'm guessing that
the fan keeps going for a little while after the flame is out. If so,
that seems to be when the oil smell occurs.

I would appreciate your advice/thoughts.


If the service co. inspected and found no leaks
in the heat exchanger, it's possible that the
burner emits a "puff" of unburnt oil vapor
upon shutdown. The fan does continue to run
after the burner cycles off and there may be
a small leak on the return ducting near the
furnace which pulls in the "puff" from flameout.

All conjecture, but this kind of thing does happen.

Jim