Musty AC Smell

[bresdogsr]

I had to have the seal changed on my rear Dometic AC. I have a musty smell in the AC unit. The smell is near where the filter mounts on the unit. I have removed the cover and could not find anything in the housing on the roof side. I cannot find any sitting water, although some may have accumulated before the seal was replaced. Any suggestions to clean or remove the odor. I have some damp rid in the bedroom for the time beong. Thanks in advance.

[cfsoistman]

Most likely the smell is coming from the dust that eventually sticks to the evaporator coil. It gets damp and that creates the smell. Same thing happens with electric heat packs and your furnace. The dust get on the element or heat exchanger and the first time it's used the smell of cooking dust is in the air. You can use a coil cleaner to desolve the dirt on the coil and rinse it off. Be sure your unit is unplugged before attempting this. Be careful with the hose so you don't end up with water dripping through the unit into the RV. Also inside take a can of compressed air or an air compressor and blow out the cabinet. There will be dust behind the little parts where a feather duster just won't reach.

[VinceU]

Originally Posted by bresdogsr

I had to have the seal changed on my rear Dometic AC. I have a musty smell in the AC unit. The smell is near where the filter mounts on the unit. I have removed the cover and could not find anything in the housing on the roof side. I cannot find any sitting water, although some may have accumulated before the seal was replaced. Any suggestions to clean or remove the odor. I have some damp rid in the bedroom for the time beong. Thanks in advance.

Agree with Charlie on cause, happens in older cars often. One way to prevent the build up is to operate the A/C as "fan" for 10 minutes before its secured after every use. This will dry the moisture on the evaporator fins which is part of air conditioning. This is where the fungi stick to and grow on if the coils are laid up damp.