What Causes That Strange/Stinky Smell With Heat
Last winter, I noticed a stinky strange smell blowing into the air when the heater was running once in a while. This winter, it has happened again, yet gets worse and worse. Now, it's 5 or 6 times per day out of the running times the heater is running.
It's definitely not the burning smell when the heater starts to run for the first time in winter while it has not been used for a while. I don't know how to describe the smell, yet it is the SAME smell 3 years after I bought a brand new car. It never happens in Summer time but only in winter when the heater is running, both the car and the house.
Is there mold or something in the duct? or an animal???