On 10 Dec 2006 06:38:43 -0800, "Restaurant Guy"
wrote (with possible editing):


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.

Well, I don't know so much as a tame crow, but it certainly sounds
like there is a hole in the heat exchanger. That separates
circulating air and combusting oil. The fan runs while the heat
exchanger is warm enough to actually heat the air so it (the fan) will
continue to run for a while after combustion stops. The hole might
be small enough or in a place which evades detection. You might find
it yourself by removing the gun, putting a strong bulb in the
combustion chamber and looking in the circulator.

While I am not terribly knowledgeable in this field, if it were mine
and I found a hole, I would replace the furnace or at least the
combustion chamber as I would be afraid it would eventually get larger
and spread noxious fumes.

--

Larry
Email to rapp at lmr dot com