The heater smelling like burnt hair

I am going crazy trying to remove the burnt hair stink from my air quality. I am in a rental house & since day a single it has stinked adore burnt hair when the furnace is on. For AC, the house has no stink. Once I change the control equipment over to heating, the hair stink comes back. If the furnace turns off & then back on, back comes the stinky stink. I have done everything I can suppose of to remove the issue. I upgraded the air filter a hundred times trying to improve the stink. I vacuumed the inside of the Heating & A/C system. I even stuck a scrub brush in the ductwork to do my own ductwork cleaning. I am now thinking I need an air cleaner or to get a real Heating & A/C corporation to do the work. The hair & dirt must be deep in the Heating & A/C or the ductwork. A real Heating & A/C worker with great tools could handle the work. What are the options that my proprietor will Springtime for something adore this? I am not thinking likely since my Heating & A/C does work well, it is just stinky. That is why I might go the air purification route instead. An air cleaner is not all that fancy. They are made for removing odors from the house. But, odors adore food, garbage & smoke are fixed by whole-house air purifiers. Can an air cleaner fix a burnt hair stink that the Heating & A/C creates? I genuinely hope so since I am desperate. Candles, incense & cleaning the house doesn’t do anything.

oil heater