Smell with AC running

[csigirl]

So I'm in getting things ready to go in our 2010 Georgetown 374, it's a hot day out so I turn on the AC. Not long after it starts to pretty much smell like the black water.... I have not even run any water, or been near the toilet area. And its not full either. does the AC unit maybe draw in air from a septic vent or something. Anyone ever have thus odd problem. It's kinda of stinky and I'm hoping the air isn't going to smell like this every time we use it. We just bought this unit in the fall.
Thanks

[msm1827]

Try changing the units filter and is it cooling.



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[ramair]

make sure that the toilet is holding water if there was no water in the toilet then it could have brought up some fumes from the black tank or the fumes from the gray tank. Insure that all sinks have had water run through them to insure that the p-traps have a barrier in them. This should stop the smell...

[Big Bill]

Is this the first time using it sincce fall? It may need airing out? Maybe moisture build up in vents? Being a 2010 this problem should have been addresed earlyer, like a vent problem. good luck

[csigirl]

We have used it a couple times and there was no smell from it. The AC is cooling. The toilet is holding water and there was no smell from the tank or sinks, toilet area... until I turned on the air then the entire motor home started to smell. it gradually got to be less but still there.
I will try changing the air filter for sure but I have a feeling it's something else going on.
Thanks for tips

[Krazymace]

Does the smell go away when the AC is off?


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[MOODMAN]

Used to work for an A/C manufacturer. Had this issue with some units sold on the market.
One thing to remember is that the coil that makes your air cold has to have a good outlet for the condensation water when running. There is a pan that holds the water, and that pan can sometimes get clogged. This is the source of the water that drips off your roof when AC is running.
Anyway, if that pan is clogged, or if you parked your unit on a non-level place, old water can and does accumulate in that pan. It can get rancid, full of algae and fungus. When you turn on a unit after sitting, you will smell whatever is in that water or was growing in that pan.
My advice would be to go on the roof, take off the AC cover, and investigate if that pan has water in it or if it is clogged. If so, clean it out with bleach. While up there, check if the condenser coil (the big one you see at the back of the unit) is clean of debris.
And, following the advice of others, ensure the inside air filter is clean.
This should fix the problem.

[Grampa Jim]

Moodman is right....I was in the AC business for over 40 years. If the AC was sitting dormant for a while,,,stinky mildew might have overwhelmed the unit. A simple but incomplete fix is to spray Lysol or Bleach Spray while the unit has been running for about 10 minutes on the inlet after you remove the filter. Let the AC run a little bit for the coils to get wet,,,,then do the spray thing. If you're mechanically minded you can take the cover off the evaporator chamber,,,,,,and do what Moodman said. The evaporator chamber is where you'll discover the "other" coils that you don't normally see. Have some putty with you when you do it, because you're going to want to make sure the evaporator chamber cover is sealed well. Also.....when you take the filter off,,,,,look with a flashlight at the intake side of the evaporator coils,,,,those are the ones that get cold.....see if they're coated with crap. If so,,,,,they and the drainpan need to be cleaned up.

[csigirl]

This is great advice. It has sat fir a bit in the driveway, not so level, as well previous owners left it sitting as well. Will get hubby up on the top to make sure its all cleaned up, Moodman and Grampa Jim
Thanks to everyone,

[saltyman]

Be sure and look for dead critters in the A/C when you have the cover off. Mice and Wasp can get into anything>>>>>>>>>>>>>>>>>

[Grampa Jim]

Oh,,,,,yes.....Saltyman....I forgot to mention that. I've dug a nest of mice out of more than one over the years. While you're at it,,,make sure there're no mud dauber nests on the condenser blades. If there was,,,,,you'd think that a plane is getting ready to crash on your roof with all the vibration it makes. I had a customer call me once with those symptoms, and I told him what it was.....silence on the phone,,,,,he thought I was full of beans,,,,,when I got there and showed him,,,,,I was the greatest thing since sliced bread. Diagnosing over the phone? How could that be??? Hey, experience is a great teacher.

[Harkerr]

Likely mold/ crud decaying up in the ac unit. Take cover off and inspect. Disinfect the coils and ducts and drains.

[Iggy]

Possible a nasty dead bat?

[BobFlorida]

I had exactly the same problem. I did what Moodman outlines and smell is gone. Be sure you go the extra step -- get some AC condenser coil cleaner and spray and then rinse the condenser coils when you have the cover off. My coil was practically plugged. Now the unit doesn't smell and it significantly improved the cooling by cleaning the condenser coil as well.

[MOODMAN]

csigirl,
Not to make you paranoid or anything, but this can also be a health hazard, besides just being a bad smell. I would advise ANY one who has a camper with a bad smell in their AC to inspect their units for this condition. Just covering up a smell doesn't remove the source, or the hazard.
Good luck!

[MOODMAN]

Oh, and one more thing...
If you are able, running a camera in the ductwork wouldn't be a bad idea to check for mold in there. That could be a source of the smell. The mold could get there because of the AC unit ducting that bad air throughout the RV and when mold spores get dispersed, if they find a good place to land, they will start a colony of growth if there is enough moisture.
Lacking a camera, you could turn on the furnace and see if it smells also. This would narrow it down to the ducts and you could rule out the AC as the source. However, the furnace on most campers uses a different duct system.
There are businesses that specialize in duct cleaning for houses. They might do your RV if you talk to them sweet

[glenn56h]

05 gtwn 375 ts how often do you replace the air conditioner seals/gaskets ??


how do you accomplish this?? is it a big job?


Thank you

[DickiedooFlagman]

Our AC began to smell after one winter of outside storage. Turns out the AC was installed incorrectly allowing some water to get into the ceiling ducts where it began to mould. We tried a number of remedies, but in the end FR addressed the problem by completely replacing the entire roof which included new ducts.

[Grampa Jim]

Glenn56h....there are no seals or gaskets that you have to worry about. If you open the evaporator chamber to clean the coils, you just have to make sure you have "dumdum" putty to make sure its sealed as it was before you open it up. Don't misunderstand me....When you take the big plastic cover off of the ac unit on the roof,,,,,the coils you immediately see are the condenser coils.....hose THEM off and make sure you don't hit the motor with water....a little smattering is ok,,,but don't hit it directly....and don't have such high water pressure that the fins on the condenser get folded in. The evaporator coils will be exposed when you take the metal cover off which is the top of the evaporator chamber. Upon inspection, you can brush them off with a toothbrush.....don't try hosing them off....that'll ruin your day when you get back down inside the rv and realize what you've done.