Tips for Efficient Flushing of an RV Holding Tank

rv holding tanksThe last thing you want to do while taking a road trip is to have to pull over in order to dump and clean the holding tank. Do not overthink this process and let it get in the way of you enjoying your time on the road. Though it is not a fun job, it is not a very difficult one either. As long as it is done properly and routinely, you should have no issues with your RV holding tank during your travels.

Here are some tips to help you efficiently flush your RV holding tank:

Gather all of the supplies you will need before flushing your tank at an approved RV waste site or connect up to one at the campsite. Supplies needed include a hose dedicated to dumping gray and black water tanks, flush hose, hand sanitizer, disinfectant wipes, and a good pair of heavy disposable rubber gloves. Some seasoned RVer’s use an inhale filter, however done properly, you won’t have to much odor when dumping.

Your first step is to check the dump valves (the large one is for black water and the smaller one is for gray water) to make sure they have both been closed. An open valve means there will be waste water at the cap and you’ll have quite a mess when opening it. With your gloves on, remove the sewer cap and attach the clear adapter to the drain valve. This product allows you to see when clean water is flushing through the tanks. Add the dump hose to the adapter and ensure there is a tight seal before continuing.

Carefully carry the hose to the sewer connection or the dump site’s drain system and attach the hose. Most dump hoses have special engineered fittings to make a secure connection. If not, you will need some type of weight on the hose to keep it down in the dump station hole.

Pull the valve on the black water valve to empty the black water tank first. If you have a black water tank flush, attach a garden hose and run water at the same time to help flush out the solids. If you do not have a black water tank flush valve, run water through the toilet by depressing the lever at the toilet. This will take 2 people as one will need to watch the flow. You can also run a hose through the bathroom window and connect a toilet wand.

Once the flow seems to be clear, it’s a good idea to close the valve and fill the tank up with water to about ½ full. Open the valve again and you will be amazed at how dirty the water is after it seemed to be clean! If you have more than one black water tank to dump, always dump the back or furthest away from the valve.

After the second flush of the black water tank, close the valve and open the gray water tank valve. This is much cleaner shower and sink water and will make it easier to clean the dump hose when you are done. Once done, disconnect the hose from the sewer dump and the RV. Carefully coil up and place in its storage area. Securely close the drain cap and make sure all valves are closed.

Run additional clean water in both tanks and add an approved tank solution to the mix. This will help clean the probes, lubricate the valve, keep odors down, and disinfect. Only dump the tanks when they get more than ½ full to help get rid of solids in the tank.

Discussion
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51 Responses to “Tips for Efficient Flushing of an RV Holding Tank”
  1. Lee

    My Black water does not drain. I believe there is a blockage. Any idea’s for overcoming this condition?

    Reply
    • Customer Service Techs

      Hi, Lee. Thanks for visiting the RV Repair Club site and the opportunity to assist with your black water tank issue. A few questions first; Does the tank currently have effluent inside and nothing comes out when you pull the valve? Have you verified the monitor panel is reading correctly? It could show 1/2 or full but really be empty with a false reading. Is the black water valve actually opening? Does the gray water side dump?

      The first step I would take is to dump some Black Water Tank Cleaner into the tank and let it go to work. There are several types, but Campco and Thetford Aqua Kem are the two most readily available and seem to work well at dissolving content inside a tank. Many seasoned RV veterans swear by Dawn Dish Soap (the blue kind) as it is proven to dissolve oils and such (remember Exxon Valdez and the ducks in Alaska?) and is biodegradable. You might need to try this a couple of times.

      Next I would try using a black water flush wand hooked to a garden hose sticking it down the toilet only if the tank is partially full. Sticking a spray wand into a mess of black water would not be a good idea.

      If none of this works, you will need to break up the clog from the outside with a plumbers snake or basically “roto router” it through the drain pipe. This is VERY messy and extreme caution should be taken to protect yourself and the surrounding area of your rig and ground from the sewage that will probably come pouring out. It’s probably best to hire a qualified plumber who not only has the proper equipment, but is trained on containment of sewage and disposal. The qualified plumber will use a wire snake with a cutting head and open the drain valve, insert the snake, and feed/push the turning snake up through the drain pipe to the black water tank. When the snake breaks the clog loose the sewage will come rushing out, that’s why it’s important to have the proper sanitary equipment and containment system. Not something the average RVer would be prepared for.

      Just a note; DO NOT use a pressurized drain cleaning method like the “Clog Buster” hooked to a garden hose, or “Clog Hog” hooked to a pressure washer. These will create extreme pressure that will blow back out the toilet and inside the RV!

      Hope this helps “dump” your black water problems and thanks again for visiting the site.

      Reply
  2. Eric

    Thanks for this xlnt post – my problem may be related. Last weekend when I camped at Tom’s Cove the odors from the bathroom were intense – but only when I kept the drains closed. Once the valves were open the odors cleared. I suspect the tank vent is obstructed by a birds nest or mud daubers but did not check it while there. Can you confirm this suspicion or is there another possibility?

    Reply
    • Customer Service Techs

      Hi, Eric. Thanks for the post and yes, it’s most likely a vent. There should be one on top of the unit that needs to be checked, however several manufacturers use what we call a “cheater vent” inside the cabinetry as there is not a good way to vent up through the coach and to the top. Usually you will see these in the kitchen lower cabinetry, or by a pantry. Look underneath the sink and see if you can find a pipe coming up a few feet and a cap on the top? This has a rubber diaphragm that is designed to allow air in to vent, but not out to keep odors contained. These do weaken and can create an awful smell inside the coach. There is a video in the Plumbing and Waste Water section titled “RV Tips for Diagnosing Waste Water Odors” that shows what this vent looks like. Also check to make sure your seal in the toilet is making a good connection. Good luck and hope you come out smelling like roses!

      Reply
  3. Billie

    my black water tank is full & clogged can’t get snake to tank can I use 2 packets of walex bio pac digester ? any help would be helpful as we live in it full time .

    Reply
    • Customer Service Techs

      Thanks for visiting the RV Repair Club site and sorry about the issue you are having with your black water tank. You could try doubling up the digester, however I doubt
      that would help much. Here’s the steps I suggest to troubleshoot the problem. First, verify the tanks are actually full, not just the monitor panel giving a full
      reading. Second, make sure when you pull the black water valve handle that the valve is actually opening! It could be the handle/rod connected to the valve that slide across
      the dump pipe is broken or disconnected and the valve is not opening. This is still a pretty major problem, but could possibly be screwed back onto the valve by turning the handle? Otherwise you have blockage in the dump pipe or at the opening of the tank. You stated “Snaking does not help? I assume you ran the snake from the inside of
      the toilet? This will probably not get to the opening and the tube from the toilet. Usually a blockage of this type occurs when there is no water in the bottom of the tank to dissolve solids or the valve is left open continuously and the liquid runs out but the solids stay and build up over time. If it is blocked or has a broken valve about the only thing you can do is take it to a service center that has a dump station with a funnel or basin customized to cut off the dump valve and snake it from the outside. A
      messy situation. You can get some professional septic system cleaning companies to extract the sewage out from the toilet using what we call in the industry a “honey
      wagon”? Good luck!

      Reply
  4. Richard Reynolds

    There is a product that can help with black water tank issues. It is called “Digest It”. It has helped me in getting the sensors working and helps clear out the tank. I use it prior to winterizing my 5th wheel. Fill the tank with water, add the quart of “Digest It”, let set for 24 hours during which time drive the RV some to stir thing up. Dump and refill with water and dump again. This really cleans things out and makes next year much more fun when RVing comes around again.

    Reply
  5. Lawrence Fidler

    Do you have a posted Check list that I can down load? This would be a pre departure check list.

    Reply
    • jean.wozniak

      Hi Joan. Thanks for visiting the RV Repair Club site. If you have dried waste in the black water tank, you will need to start with warm or hot soft water filling it up over 1/2 of the tank and add a chemical from Thetford called Aqua-Kem a black water tank cleaner. You basically need to re-hydrate the solid and wake up the bacteria. If it’s really bad, you will have to fill and drain several times letting it set for a couple days at a time! Some RVer’s have had success with Ridx or similar septic tank cleaner. You may also try a black water wand which you stick down the toilet and it sprays in every direction. A last ditch effort would be to hire a pressure washing cleaner to snake a drain cleaning nozzle on the end of a pressure hose either down through the toilet, or up through the dump valve.

      Reply
  6. Kevin K

    Do you have to worry about leaving a flush hose hooked up from a “y” fitting in your fresh water supply. Can it contaminate fresh water supply?

    Reply
    • jean.wozniak

      Hi Kevin. Thanks for visiting the RV Repair Club site. I assume you are describing the “flush hose” as a hose connecting to the black water tank flush valve? I would not connect this to an “Y” fitting without a backflow prevention valve. It shouldn’t backflow, but I’ve found over the years to never say never! And since you would only flush the tanks when dumping, that system isn’t used very often so maybe a different hose and quick disconnect?

      Reply
    • Customer Service

      Hi Lou. Thanks for visiting the RV Repair Club site. There are several products available for reducing the odor in RV holding tanks. Thetford makes both a liquid and powder packet product that you pour down the toilet for the black water tank and down a sink or shower for the gray water. Another important part of keeping odors in check is to properly dump your black and gray water tanks which you can find videos on in the plumbing section on the site. It’s also a good idea to periodically sanitize the black water tank with a bleach and water solution. Depending on the size of tank, pour about 2 cups of bleach and 20 gallons of water in the tank and let it slosh around. You do not want to do this to often as the bleach will kill the good bacteria you want to digest the waste in the black water tank.

      Reply
  7. susan

    I am trying to find a video on how to fix my toilet in my RV, it seems that when I tried flushing it. the handle would not open the circle in the to put the water out of the toilet. I was wondering if you could help me.

    Reply
    • Customer Service

      Hi Susan. Thanks for visiting the RV Repair Club site and the opportunity to assist with your toilet issue. If you push the handle down and the valve does not open, you probably have what we call a broken “flapper” valve. The only way to repair it is to remove the toilet which is probably a messy job at the point your at? We currently do not have a video on that procedure, however if you can give me the make, model, and year of the toilet, we can provide some detailed instruction on removal and repair. We do have this topic in the list for shoots coming soon.

      Reply
      • Jerry

        RV Make: Jayco, RV Model: Eagle, RV Year: 2003

        Susan, I have the same problem. Mine usually occurs when I take it out of storage. I’ve learned to lightly press down on the valve with a screwdriver or pencil to unstick it. Don’t press to hard as you may break the valve. Be sure to properly clean the tool after use.

        Reply
  8. Lee

    Good day! Love the site. I have a question. I have a 2008 Jayco that I live in full time. There seems to be a sewer odor coming from the outside of the toilet area. The odor is more noticeable outside the toilet door more as I am walking down the stairs. There is a closet backing the toilet that can have an odor smell as well. I have replaced the toilet, cleaned out the top of the vent pipe and installed an odor withdrawer on the top of the pipe on the roof. I have cleaned out all my s traps under the sinks. It’s like the vent pipe has a hole…any suggestions?

    1

    Reply
    • Customer Service

      Hi Lee. Thanks for visiting the RV Repair Club site. Since you reference “coming down the stairs” I assume you have a fifth wheel trailer? Many trailers use what we call “cheater vents” which are vents that come up from the tank into lower cabinetry and have a vent cap that is supposed to keep black tank smells from escaping while drawing inside air to vent. They use these because the floorplan will not allow a full pipe to go all the way up to the ceiling. These are usually under kitchen cabinets or inside closets? We had to replace one in a 2014 Raptor Toy Hauler this year and found it hidden inside a corner cabinet beside the refrigerator! Found one at Home Depot and replaced it, smell is gone! Another place to look is making sure the vent pipe is still connected to the tank? There are instances where the pipe comes loose or cracks at the tank. This is a much more difficult inspection as it’s often times hard to see and it requires removal of the tank. I would suggest checking out the closet for a false floor and possible cheater vent first.

      Reply
  9. Michael

    RV Make: Keystone, RV Model: Laredo, RV Year: 2009, Brand: Keystone, Model Number: 5th wheel

    I need to replace the rubber seal on the outside of the window but can’t find a video

    Reply
    • Customer Service

      Hi Michael. Thanks for visiting the RV Repair Club site and the opportunity to assist with your window seal question. Most manufacturer’s use Butyl tape which is a soft putty like tape between the window frame and the sidewall. We do not have a video on that repair as yet, but it is on the list. In the mean time, you will need to remove the window to apply new tape. Inside the rig, the frame is screwed to the outside frame which “sandwiches” the window to the sidewall. Have someone outside holding the window and remove the screws inside. You may need to pry the window frames off as they do have a tendency to stick over time.

      Reply
  10. Charles

    RV Make: Heartland, RV Model: Wilderness, RV Year: 2016

    Before stowing the unit we put treatment in the black tank after we flush out with two toilet bowls of water. The unit might sit for a few months before being used again. Leaving the treatment and some water in the tank. Is this the correct way or will this cause problems by leaving the treatment in for so long. If so what is the proper way.

    Reply
    • Customer Service

      Hi, Charles. Thank you for visiting the RV Repair Club site and the opportunity to assist with your storage question. You can leave treatment in the tank during storage, however I would suggest a small amount of RV antifreeze and valve treatment rather than sewage chemical as it’s less expensive and will condition the rubber seals. The tank treatment you put down it will not do any damage so leave it for this year.

      Reply
  11. Steven

    RV Make: Keystone, RV Model: Springdale, RV Year: 2002

    When I open my toilet to place the cleaning wand in, I discovered it wasnt directly ove the holding tank. The schedule 40 pipe is at a 45 degree angle for about 2-3 feet to the tank. What can I use to get some water action in the tank itself?
    Steve R

    Reply
    • Customer Service

      Hi, Steven. Thank you for visiting the RV Repair Club site and the opportunity to assist with your holding tank cleaning issue. Camco makes a flexible black water tank wand that will “snake” through your 45 degree angle and get down into the tank. If you have access to the side of the black water tank, I would recommend installing a permanent mounted black water flush valve.

      Reply
  12. Ward

    RV Make: Winnebago, RV Model: Via 25P, RV Year: 2016

    As to the black water dump procedure, I was surprised to see you advise to hook up to the RV before hooking up to the waste line in the ground. I understand it is important to have the waste line ready to go, just in case there is waste in the RV line when you remove the cap. This way any waste you direct into the hose goes down the waste line, not out on the ground.

    Reply
  13. Ron Byrd

    RV Make: American coach, RV Model: class c, RV Year: 1986, Brand: Aqua Magic IV, Model Number: can't find

    2 questions 1 my toilet stopped rinsing, it was working fine then just quit,any ideas as to why? 2 the pump under the sink is leaking from the bottom of the plastic front of the assembly pump, is this fixable or do I need a new pump?

    Reply
    • Customer Service

      Since the pump is leaking, this could be the cause of your rinsing issue as well. Depending on the make and model of the pump, you should be able to repair it with a set of o-rings or a new assembly. Check out the water pump video on our website under plumbing. If the pump is leaking, it probably doesn’t have enough pressure to get back to the toilet? Otherwise it’s in the water valve or hoses supplying it. You will need to take off the hose supplying the valve and verify you have pressure. Once you get the pump fixed, take the hose end and put it into a bucket and turn on the pump. You should have water there, then disconnect the supply valve and reconnect the hose to see if you have pressure when the handle is depressed. It could be a kinked hose going to the opening in the toilet or even clogged opening in the toilet itself.

      Reply
  14. Jim

    RV Make: Triple E, RV Model: Regency XL, RV Year: 2000

    I have recently been using a simple mixture of 1 cup Borax and 1 cap full Colgon liquid in the Black Water tank when traveling. This works best on days that we are driving as it splashes around in the tank. It helps to soften any solids and also cleans the sensors. I also use a 1/2 – 1 cup of Dawn (blue) dish liquid in the grey water tank to keep the sensors clean, and have found it to be the best product for this purpose as it cut through the grease.
    Another fine product is a boat tank cleaner “Head Shock”. Use a 1/2 bottle at the end of the season, let it stand in the tank for 24 hours and flush.
    Finally, spray a silicone lubricant on the drain handle rod to keep it moving smoothly.

    Reply
  15. Bob Deuley

    RV Model: Heartland , RV Year: 2009

    Once the unit has been flushed, I typically dump 1-2 bags of ice in the toilet and as the ice melts going down the road; the slushing of the cubes does an excellent job of cleaning the sides of the tank.

    Reply
  16. R Statt

    RV Model: Sunseeker, RV Year: 2016

    The best way to avoid toilet lines plugging while parked is to leave both of the water valves shut, and keep the water in the tanks until full.It allows the solids in the black water to break down so they flush easily and when you do dump the black tank, I leave the black water valve open for a few seconds at the start of the grey water dump so the grey water also rushes into the black water tank initially as its dumping . Then I quickly close the black water valve until I’m completely finished with the grey water and then open the black water valve again , it seems to help keep the black water valve clean and sealing without leaks into the cap. Sometime at the end of a road trip I flush down the toilet a 1/4 cup of Powdered HE laundry detergent (no foam) and fill the black tank 1/4 full and do a final dump using the tank flush before parking .

    Reply
  17. Bob

    RV Make: Tiffin, RV Model: Phaeton , RV Year: 2009, Brand: Sewage tank

    Road clean your black water tank by dumping a small bag of crushed ice in the toilet. Hold the toilet dump valve open as you pour the ice into the toilet so it doesn’t jam as you pour it in. Drive your RV and let the ice slosh around in the tank busting up the solids. Then dump your tank at a dump station or campground. I also periodically use Calgon water softener to coat the inside of the black water tank makes the walls slick and helps to keep waste from sticking. I use a cup when I put sanitizer treatment in the tank.

    Reply
  18. Fred

    RV Make: Four Winds, RV Model: Chateau 31, RV Year: 2000

    Inaccurate Grey Water and Black Water Tank readings.

    Reply
  19. Pierre-Louis

    RV Make: Jayco, RV Model: 186, RV Year: 2007

    I been using a mix of 2 product to keep my tanks clean without the bad smell . Tide and Calgon in the tanks. It desolve, clean and smell good. 2 part of tide in on part of calgon mixed with 4 quarts of warm water pour in the black water tank and voila, no more bad smell. Flushing the tanks is the most important solution before adding any product. My solution works. (Sorry for my bad English)

    Reply
  20. George Bassett

    RV Make: Jayco, RV Model: Sport, RV Year: 2007, Model Number: 165

    My monitor for my Black water tank shows 3/4 full, no mater if the tank is empty. This is a bother, because I really don’t know if it is or not. How can I fix it, so it shows proper levels. Thank you.

    Reply
  21. Fred

    RV Make: Montana, RV Model: 3025 RL High Country, RV Year: 2015

    My first experience with my fifth wheeler after I purchased it was an issue with mislabeled dump handles. We had a dedicated area to dump grey water and when we got to a proper facility we could dump the black water. Well to my surprise the grey water was not showing on the panel that it was going down when dumped. Little did I know it was the black water that was being emptied until someone complained of the smell. I went to the dealer and told him the grey water was not dumping. After they complained they told me they dumped the tanks and there was nothing wrong. Having been born at night but not last night I thought I would check it my self. So when I got home I put clean water in the grey tank and pulled the handle. You guessed it nothing came ou. I then pulled the black tank handle and the clean water came out. I since found out there were at least two other Keystone trailers with the labels reversed. Needless to say the PDI was not very well done. So, buyer beware.

    Reply
  22. Dale

    RV Make: Thor, RV Model: Chalenger, RV Year: 2012

    I believe the black/gray water flush connection is plugged. What is good way to clear the opening?

    Reply
    • Customer Service

      I would suggest removing it and soaking it in CLR or white vinegar. You can get CLR at any home improvement store, hardware store, and even grocery stores, it’s the green bottle with Calcium, Lime, Rust (CLR) listed and is typically in the section with toilet cleaner. Depending on the model, you may also be able to run a round wire brush through the opening once it’s removed.

      Reply
  23. Joel Cummings

    RV Make: Lance, RV Model: 1685, RV Year: 2016

    I would just like to add, that when performing these operations on your RV, you might want to put on a pair of safety glasses to protect your eyes from any material that could become airborne and lodge in your eye. It would be good to add safety glasses to your kit of materials needed for your RV. Thanks so much for your website. I am learning
    so much from it since this is my first year owning an RV.

    Reply
  24. Michael Wallace

    RV Make: Newmar , RV Model: Kountry Star , RV Year: 1996

    Which valve opens the water flush when I try to flush by hooking up the water hose to the flush it does not put any water in to the tank.
    Thanks,
    Michael Wallace

    Reply
  25. Lloyd

    RV Make: Tiffin, RV Model: Phaeton, RV Year: 2008

    It’s been three months since my purchase and we’ve taken a few trips. We flush both tanks before each trip, but as we travel down the highway, we often get a toilet smell in the RV. The smell lingers for a while during a trip. What can we do to correct this problem? Thank you.

    Reply
    • Customer Service

      I would start by sanitizing the black and gray water tank using about 3-4 cups of bleach for a 50 gallon tank and then fill 2/3 with water. Drive around and then let it sit for a few hours before dumping and refilling with fresh water and dump again. Next, find out what sinks dump into the gray and if possible one that dumps into the black. You can do this by letting a faucet run and watching the monitor panel. Most sinks dump into the gray water, however due to floorplan designs and obstructions, some sinks dump into the black water and if you are running down the road, the water in the P trap splashes out and the smell from the tank will come up into the coach. Also, check your roof vent. Both tanks should have a vent pipe going up to the roof to allow water flow and you will get smells coming from there. If the vent is plugged, you will get smells inside the coach. Check to see if you have a “cheater vent”. This is a vent that can not run up to the roof because of an open counter or other obstruction going up so the pipe is cut short and a vent cap is under the sink or in a back closet. If the vent cap becomes weak, smells will come inside the unit. This happened on the 2014 Raptor we were shooting on so check out the video here:

      https://www.rvrepairclub.com/video/rv-tips-for-diagnosing-wastewater-odor-in-your-rv-008152/

      Reply
  26. Battiato, Helen

    RV Make: Itasca, RV Model: Class C, RV Year: 2001, Brand: Norcold, Model Number: Itasca Spirit

    This is in a small 24 ft Itasca. After a few days, my Norcold Refrigerator stops. Then I up the temperature and it goes back on and is fine. Why does it do that? I’m worried that I might have to replace it soon.

    Reply
    • Customer Service

      To provide more specific troubleshooting information we need to know the model and year of your Norcold Refrigerator. Let’s assume it’s a two door freezer on top and refrigerator on the bottom model. Inside the refrigerator attached to the fins on the back is what’s called a thermistor which is a sensor that sends the temperature to the control module telling it to start up again because the temperature is getting warm. If the thermistor is place low on the fins, and you don’t have good air flow in the refrigerator, the warm air will rise to the top and the thermistor senses colder air. Make sure you have good air flow by not blocking shelving inside and place one of the 9V small fans inside. Then move the thermistor up higher on the fin. Make sure it’s not covered in frost or ice. If it keeps doing this, you will need to test the thermistor with a Multi-meter. Check out the video in the appliance section on the site.

      Reply
  27. Barbara

    RV Make: Thor, RV Model: Palazzo, RV Year: 2014

    my toilet is clogged about a foot to a foot and a half down the toilet opening and I can’t get it to go down. Any suggestions? Thanks.

    Reply
  28. James

    RV Make: fifth wheel, RV Model: highland ridge Mesa ridge , RV Year: 2017, Brand: Mesa Ridge, Model Number: 337RL

    We are on 2nd trip and still getting an odor from the black water tank into the bathroom. Have flushed it
    several times and add an extra pouch, but still an odor, so what can be done to get rid of it.

    Reply
  29. Christie

    RV Make: Fleetwood , RV Model: Utah , RV Year: 2004, Brand: Thetford

    My used camper came without any hoses. What do I need to empty and clean it? Thanks. Christie (I have a picture but don’t see how to upload it to you.)

    Reply
  30. kim

    RV Make: Keystone, RV Model: Hornet , RV Year: 2004, Brand: custom design-system monitor

    We have our monitor that doesn’t seem to be working correctly. Gray water and fresh water lights work fine. Black water always reading empty. We’ve cleaned sensors using a sensor cleaner and the swizzle stick. Water runs free and clear coming out of holding tank. Not sure if maybe it’s our monitor panel that’s gone bad.
    Please help !

    Reply
  31. lynnbsml

    RV Make: Jayco, RV Model: Alante 32N, RV Year: 2017

    On hot days I am getting tank odors from the forward air conditioner. What’s the cause and the remedy?

    Reply
    • Customer Service

      Hello,

      Is this a motorhome and you are talking about the AC on the engine? Or are you talking about a roof mounted AC? An engine AC could be pulling smells from the outside into the cab. You would want to select the air flow option to recirculate the cab air. A roof mounted AC is sealed at the top and shouldn’t be bringing in any smells. It pulls the air from inside, removes the heat and then sends it back into the coach. If you are getting a smell from the roof AC, it is possible it has a bad gasket around the fan motor or the mounting gasket. If your black tank roof vent is close to the AC, fumes could be getting in. Remove the shroud to the AC and inspect the gaskets and also check the cover going over the evaporator in the front. There could be openings allowing outside air in.

      I hope this helps,

      Dan
      RV Repair Club Video Membership

      Reply