oil burner smell

[Pennwalt]

Five years ago, I got a new oil burner heater installed. Even before the new burner was installed, I started noticing a strange smell when heat started flowing from the ducts. The smell is difficult to describe, but it has come and gone for about 6 years. Over the last 3 years, the smell, when it comes, has declined somewhat in intensity. At first, I could hardly stand it. I have had HVAC people look into it and they claim they can't smell anything. Sometimes it's so subtle that you hardly notice it's there and then the next morning it returns pretty strong. Not sure what to do about it, but I'd like the smell eliminated. Any idea of the cause and what steps to take to cure it? Thanks, Pennwalt

[Stormin Mormon]

Could be any of a bunch of things. Might be dust in the ducts, or dead mouse in the ducts.

[Alexander]

Stop using the Ductwork as a dirty laundry chute.

[.p.jm.]

I was thinking 'stop renting it out to Grandma and telling her it's an old folks home'.

[Existential Angst]

Does the boiler room have any odor? It could be the blower sucking in ambient boiler room air through gaps in the unit. Differential barometric pressure can greatly affect this as well, causing building odors/gases to naturally vent OR accumulate, thus the intermittent effect. This effect can be very instantaneous, almost literally second by second, depending on local conditions, or last for hours or days.

There could be a hidden intake register somewhere, picking up something stored or decaying. Plant material/water can be pretty wierd, smell-wise.

You might try getting the blower to come on without heat, and see if the odor appears. That would at least eliminate the heat component as a cause.

You'd be much better off posting on alt.home.repair with a Q like this -- or really any Q on hvac. The effing character-disordered idiots here are too busy jerking each other off to be of any use. I think alt.hvac might be a disguised dating service for closet pervs/broke-assed hvac techs still living with their mommies.. ahr has quite a few knowledgeable cooperative regulars there, willing to help.