Bad Odor Smell From A/C Heater

Vehicle A/C Heater Smells Bad

Bad Odor Smells Like Mold

Q: Whats the reason  I get a bad odor when I turn on the vent, heater or air conditioner? Is this smell bad for my health ?
Its very much unbearable?

A: Breathing mold spores is not good for anybody's heath! Why is there mold in your ventilation system?

There are few possible reasons for such smell to be noticed.
Below i wil explain in much detail:-----

Either water is not draining correctly, there is tree and leaf type matter collected in the system or rodents have stopped in and laid the ground work for a new housing development.

If your vehicle is equipped (it would be great to know what you have for a vehicle) with a cabin filter then it may need replacing.

For those of you who do not know, many of today's vehicle have a filter for filtering the incoming air for the passenger compartment.
This filter works great and I think it's the best thing since milking parlors! If you grew up on a dairy farm you'd understand.
Also cabin filters can be upgraded with charcoal filter elements.
With these filters you can hardly tell you're following a smelly diesel truck.

In any case your vehicle's ventilation system needs a cleaning, rotor rooting, rodent routing or a new cabin filter.