What can ido to get rid of musty smell

the drain plugs are located under the floor mats in the floor pan . If you look from underneath you will see the round plugs .If the carpets have been wet that bad then you will never get rid of the musty ( fungus) smell . consider new floor mats

Ensure filters are all clear and try using tumble dryer sheets to fragrance clothes which should get rid of musty smells.

Most common cause is water sitting in the bottom of the a/c heater box. Make sure the outside drain is open. There are spray products for using on the vents.

Are the heaters hydronic? (Heated water flowing thru tubes) If so, the musty smell is because the water has been leaking which is obviously a problem. I know you mentioned that they are electric heaters, but "musty smell" goes hand in hand with moisture.

Use a degreaser to clean the rubber seal around the tub. Then use concentrated lemon juice to remove the musty smell.

Hi,
Here is a tip that I wrote about mold and smelly washers...

How to have a Clean Washer
http://www.fixya.com/support/r4356970-clean_washer

heatman101

You have lint built up in the exhaust duct and it retains moisture that molds.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/craig_3fa289bf857b1a3c

they should be washed every2 months use baking soda and a box of fridge charcoal

thumbs up

Once towels have had mold grow on them, it's unlikely you will ever get rid of that smell. You can usually tell a towel has had mold grow by discolorations on solid color towels. You probably need to start over with new towels, make sure they are washed and dried frequently and that they don't stay damp for long after showering. If you live in a humid climate, a towel warming rack will help with drying.

spray motor and gear housing surrounding with insecticide, roaches may be nesting there that gives out the foul odor