Oil smell from furnace (when fan is on but flame out, I think)

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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

You need a new furnace. Try a heat pump. Get a new thermostat. Bubba
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
My first question ...would be??? Do you have an oil furnace?

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Forced air oil, about 15 years old. daytona wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Make and model...some oil furnaces have problems and characteristics

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I will say it again I am not HVAC person However from mechanical point view it seems that you are having some oil residue that it needs to be burn out, you also may have draft problem check your smoke stock make sure you are not getting down flow on shut down, does your chimney is adjusted for proper draft, any chance that your furnace creating vacuum in your basement, does your ignition system shut off before the oil, defective pump shut-off valve, the air entrapped in nozzle due to restriction in supply line oil expansion in the nozzle line assy. due to radiated heat at shut down, make sure that you have makeup air at location of furnace, your chimney temperature perhaps some what low for the draft require or needed, Good luck from Dido

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Who'd a thunk?

and you think Oil, could be doing that?

smoke stock? Is he stocking cigars now?

Yes, he had the bricks rotated for proper draft just the other day.

Yeah, they all do that. I think this brand furnace is a "Hoover".

Yeah, they all do that too.

That would be called an "oil pump"

Im going to need that one in English please.

He just ordered a box of that yesterday

You have a draft versus temperature chart now? This one I gotta see Bubba

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Dido, why would one of the problems you outline below cause an oil smell to come through the registers?

--
\'Humankind cannot bear very much
reality.\' - T.S. Eliot
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I'm think he is suspecting that once the burners stop the furnace is drawing some exhaust back into the house. If the furnace is inside the house and there is a leak in the distribution side outside the conditioned space the furnace could be pulling make up air back through the exhaust. It would fit the conditions described.
Steve Scott wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Thanks all for the replies. Furnace repair is over my head, for sure. I've decided to call a different service company (and hand them a summary of your responses.) I'll report back here for your interest on what they say/find/do. Wish me luck. I don't want to have to buy a new furnace.
Brian
jamesgangnc wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I just wanted to see if Dido knew the primary reason for this issue was leaky or disconnected ducts.
On 11 Dec 2006 05:05:17 -0800, "jamesgangnc"

--
Thank you for encouraging my behavior.





Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.