Smelly air conditioner

JakesRinker300

Could the rust in the drain tray be a reason for my foul smelling air conditioning??

aero3113

Is there water in the pan or just rust? If there is water, check if the drain is clear. Is the smell coming from the ducts? Have you cleaned the filter screen?

Ian

Doesn’t look like there is a filter over the coil. The ducting likely has dust and grunge  in it.

aero3113

On my boat the filter isn’t on the coil, it’s behind the intake grill under the fwd birth.

Liberty44140

Ian nailed it. All of my boats units had outer screens to filter dust. No screen on that intake. 

Someone here recommended this to clean intakes and coils that get caked with dust. Even though I’ve always had screens I still use this every few years and it works great to clean up what makes it through the screen:

https://www.homedepot.com/p/AC-Safe-Air-Conditioner-Foaming-Coil-Cleaner-AC-921/206740351

Spyderweb

Mine has a screen behind the intake grill AND over the coil.

JakesRinker300

Aero. I’ve never checked to see if there is standing water in that tray during operation. The boat is stored for the winter but looking into the smelly air was one of my winter projects. It appears though that the water isn’t draining. The “filter” for the air conditioner is a metal screen located in the wall of the mid cabin just above the AC unit. 

JakesRinker300

Spyderweb said:

Mine has a screen behind the intake grill AND over the coil.

My coils are located right behind the seat back for the seating area in the mid cabin. 

Liberty44140

The pan drains are a little higher than the bottom so when actively using the AC on a hot day/weekend I always have some standing water in there. It usually dries after a day or three of non use. The drain issue comes when it is over flowing. Easy though to make sure drains are clear, I usually use something plastic and not a screw driver as I dont want to puncture anything. A stuff cable tie usually works well for me.

Pat310

To get rid of the water sitting in the pan and rotting it out, I added a fiberglass bakery tray under the AC unit with a flush drain. I drilled the bottom of the original pan (to go with the rust holes) to drain into the lower panI also added a washable pre-filter behind the intake vent

YYZRC

Another suggestion would be to add a wedge under the opposite end to the drain. I did this when I replaced my AC. 

aero3113

It’s hard to tell in your picture but the water line looks to be above the drain hole. So it’s possible your smell is from standing water in the pan.

@YYZRC , I did the same when I replaced mine.

YYZRC

@JakesRinker300 I highly doubt any foul smell is emanating from the AC unit itself due to the standing water in the pan. It is more likely that there is mold somewhere in your carpet/upholstery from a leak and the blowing air is exacerbating the smell. 

JakesRinker300

Liberty44140 said:

Ian nailed it. All of my boats units had outer screens to filter dust. No screen on that intake. 

Someone here recommended this to clean intakes and coils that get caked with dust. Even though I’ve always had screens I still use this every few years and it works great to clean up what makes it through the screen:

https://www.homedepot.com/p/AC-Safe-Air-Conditioner-Foaming-Coil-Cleaner-AC-921/206740351

Would you recommend applying this foaming product while it’s in service or can I do this while the boat is in storage?

JakesRinker300

Would an ionizing machine help with this odour?

Liberty44140

JakesRinker300 said:

Liberty44140 said:

Ian nailed it. All of my boats units had outer screens to filter dust. No screen on that intake. 

Someone here recommended this to clean intakes and coils that get caked with dust. Even though I’ve always had screens I still use this every few years and it works great to clean up what makes it through the screen:

https://www.homedepot.com/p/AC-Safe-Air-Conditioner-Foaming-Coil-Cleaner-AC-921/206740351

Would you recommend applying this foaming product while it’s in service or can I do this while the boat is in storage?

You can do it in storage, just do it a few days before launch. Like it says this is self cleaning and kinda just runs down in to the pan, the condensation water helps to clean the coils off. I've done it in the water and let it sit for the day, then turn the unit on, I've also done it on the hard when I knew the boat would go in and be used within the week.

It does a really nice job cleaning dust off of the coils and intake. My in-laws had a 1974 flybridge with a very old unit in it and it was freezing up. Trouble shooting lead to air flow and I realized it had no filter at all on the intake so it was caked with crap. I sprayed this stuff on in several coats over the course of several days so that it kept taking layer off. Worked awesome the entire following summer. No freeze up..... and still no filter LOL

Liberty44140

JakesRinker300 said:

Would an ionizing machine help with this odour?

Once you fix the source of the odor it should go away pretty quickly.

alex8q4

The AC in my boat had a very strong smell when we first got it.  We cleaned the screen covering the coils and it cleared it up completely.  I brought the screen home for cleaning again this winter, provided I can’t find a replacement screen.   I will be ordering the cleaning foam tonight, seems like a great way to clean the coils which I am sure are filthy.