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Best of bad situation: rusted oil furnace workaround

Javik Member Posts: 1
Another discussion of this website talks about how you can smell oil from a rusted out oil furnace exchanger at first when it turns on, but not after it's been a while, because the blower pressurizes the duct around exchanger and keeps the oil fumes from entering the ducts. I had always assumed it was just because you get used to the smell and you don't notice it.

I live in a house with a 73-year-old father who is extremely rigid in his belief that there's nothing wrong with the oil furnace. "It's just dust." He simply will not allow the 1960s Lennox to be replaced. Apparently you're supposed to clean oil furnace heat exchanger? Wow I've never seen that done. I don't think the heat exchanger has ever been cleaned this oil furnace in the last 30 years. I even hired some professional inspection company come out after an unrelated chimney fire, but they actually sided with him, and said we don't detect any carbon monoxide, keep using it.

So apparently if you're running the blower while you're running the burner, that should prevent any smoke or oil odor from getting into the ducts. The reason we smell it is because normally the burner starts when the blower off, and the blower doesn't start until the exchanger has actually warmed up.

So then, what I need to do is install a 120v relay between the burner circuit and the blower. When the burner starts, it triggers the relay, which will start the blower at the same time, which will immediately begin to blow cold air through the house (oh well....). Then once the firebox is warmed up, the blower will continue running on its own thermostat after the burner shuts off.

In theory this should keep us from smelling the oil stink, at least until that exchanger rust hole is so dang big that it actually becomes the primary air intake for the firebox, and the oil exhaust starts blowing out of the air intake at the bottom of the firebox.

I guess this hack will justify my idiot father's decision to not replace it, but I don't really have any ability to force him to replace the furnace before it injures or kills him or us.


  • Paul S_3
    Paul S_3 Member Posts: 1,257
    Bottom line....it should be looked at by a professional and then if everything's ok....then it should be serviced....any fuel burning appliance MUST be serviced and checked with a combustion analyzer once a year
    ASM Mechanical Company
    Located in Staten Island NY
    Servicing all 5 boroughs of NYC.
    [email protected]
  • Jamie Hall
    Jamie Hall Member Posts: 22,887
    That professional inspection company should be fired. If you are smelling any oil smoke from a forced air furnace, it should be inspected by someone who actually knows what they are doing. If the heat exchanger isn't rusted out -- and only if -- they should then adjust it properly. The bandaid fix to have a relay and time delay is... dangerous. At least in my opinion. What happens if the circulating fan fails and combustion gas gets into the forced air ducting? Carbon Monoxide is not something to fool with.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Leon82
    Leon82 Member Posts: 684
    I take it he owns the house?
    Have him go on vacation and replace while he's gone.
    CanuckerJohn Mills_5