I had a amer. Stand. Freedom95 vs 2 stage furncae installed about 3 weeks ago. Also had a new AC unit and Accu clean filter installed. Since the first date the unti was turned on(heat mode) we experienced a burning skunky odor. I have bypassed the electronic filter and odor is persistent. I have placed odobloc in the return duct, not helping. The smell could also be described like burning caulk. Installers state that they never heard of theis problem. Would love some guidance and suggestins.
Note. We had all the lower duct (Basement ) replaced. Had duct oard and went to galvanized.
Look for any and all responses.

How many times has this unit ran? Probably just the oil burning off the new heat exchanger. Usually goes away after 10 minutes of running on high. If it has not been cold, and they did not do a proper start up, like forcing it to high to check gas pressure then it may have not burnt off yet.

It ran for about a week and I kicked it in high for several hours, heated the house up just to see if it would go away. If the guts of the filter are removed the odor is still predominate in the lower part of the furnace