Forced air oil burner smells

Yes it could be the nozzle. Who ever cleaned it should have changed the filter and checked the pump and nozzle.

Tom

They changed the intake filter, not sure if they checked the pump and filter

Also thanks for the input

There is an oil filter, that should have been changed.

Tom

Sounds more like a problem with the heat exchanger.

Likely cracked or something broke.

How else could you get combustion odor into the circulating air?

There are thermal sensors that trip when combustion gas enters the heat exchanger.

Tom

tjbnwi said:

There are thermal sensors that trip when combustion gas enters the heat exchanger.

Tom

Click to expand...

and sensors never fail?....

griz said:

and sensors never fail?....

Click to expand...

Yes they do, in the case of the thermal switch it fails to a complete shut down.

Also the oder is stronger in the basement on start up, not where the air is distributed. Leeds me to believe it is in the combustion chamber.

Tom

Mac13 said:

Hey all,
I have a thermoflo forced air oil burner and intermediately the air blowing out of the registers smells subtilely like burnt oil an sometimes it heavier but when this happens it smell very strongly in the basement.

Had it cleaned and still does this. A friend that works on oil burners said it might be a bad nozzle.

Anyone have any ideas of what it might be? Just looking for second opinions

Click to expand...

It could be the nozzle. The nozzle should have been changed out when it was cleaned. New nozzles are sometimes no better then the old one they replaced.

It could also be that the ignition transformer is getting weak, and your getting a delayed ignition. It too should have been checked when the furnace was cleaned.

Its possible the electrodes are not set up properly and causing a delayed ignition.

One or more of the gaskets for the clean out ports may be bad and allowing fumes out during ignition.

An oil pump with a weak pressure spring can also cause fumes from a poor light off.

The oil fumes from a delayed ignition come from the fumes blowing out through the observation door/port for the combustion chamber.

There are no sensors on an oil furnace that will lock it out if fumes get into the air stream. Many oil furnaces still use a mechanical fan and limit control. it only responds to heat, and can't tell the difference between hot air and hot CO.

Others use a fan timer and a cheap disc type high limit switch. It also can't tell the difference between hot air and hot CO.

Only way to know for sure, is to test/check out the components.