New RV owner Prowler lynx 32 Need help sewer smell in cabin

Just purchased a 2019 lynx 32. We have two ACs in the unit. We have an issue where the rear unit seems to be sucking the black tank smell into the cabin of the camper. How can I keep this from occurring? How can i keep the black tank from smelling? Has anyone else experience this with this same camper and how did you fix it? We just arrived at our site. Turned everything on fired up AC and flushed the toilet. Since the smell was stronge. I made sure when we used it last the tank was emptied.

We’ve only used this camper twice. Any help be appreciated...

Go up on the roof and remove the mushroom vent covers and check if the roof to vent pipe area is sealed. Spray foam or caulk will help with that.
Remove the AC cover inside and make sure that the plenum area is sealed good. If not, aluminum duct tape will be your friend there.

Peace
Dave

I will go up and take a look at that today. As far as the ac it appears to be sealed by I’m no expert either. I’m a first time RVer so still learning what to do and not do. Does anyone have any tips that can help with the smell in the black tank? Also if anyone that has the same camper as I, do you also experience the same issue and have you resolved it? I just making sure it isn’t some defect..

thanks for everyone’s help..

Do you leave the gray tank open when hooked up to sewer?

JohnD said:

Do you leave the gray tank open when hooked up to sewer?

Click to expand...

I only ask this as leaving the gray tanks open can allow the gasses from the RV park's septic or sewer system to release up through your sewer hose and out the roof vents, which in turn could be sucked back through the RV by the AC.

If you've ever smelled sewer while walking around a campground or RV park...this is what is happening.

And the more campers that leave their gray tanks open (bad idea), the more chances these smelly gasses have of wafting around the RV park!

Here is a video in case you are (should be) interested (5 minutes long - must watch the whole thing):

https://www.youtube.com/watch?v=Q4A-41EdBBc

You can try this for the smell:
Dissolve two (2) cups of the water softener in a gallon of hot water. Then, pour the solution down the drain into the empty tank. Use two cups of softener
for each wastewater tank in your RV. The tank's drain valve should be closed otherwise the softened water will just drain out. Then use the tank(s) normally until it is full and drain it normally. Add a cup of laundry detergent to the black (commode) water tank at the same time you add water softener. This will help clean the tank. The gray water tanks should already contain soap through normal use.

If you don't find anything wrong with the black tank venting you might want to think about this.
As for your AC pulling the smell in I can give you an example of a mobile home I was asked to evaluate the oil fired furnace smoking up the mobile home. I found that the installers didn't draw combustion air from outside of the trailer as this the furnace was designed to use. Instead it pulled combustion air from the mobile home. I also noted that the mobile home owner had closed off 1/2 the trailer from the heating system in an attempt to reduce heating cost. This reduced the volume in the trailer to the point when the furnace blower fan came on it pulled air from the oil burner, thus smoke from the combustion chamber of the furnace was entering the house and further caused the flame of the oil burner to burn smokier.

How does this relate you ask? If the AC is pulling more air in than the outlet/s is allowing then the AC fan will pull air from where it can. You could try opening any roof vents to see if this will help though it seems to defeat the AC running and pulling in outdoor air. If you have a ducting system from that AC you can try insuring all the outlet vents are fully open.

If all of the above doesn't work, take a look at the commode donut and the commode flush valve seal. Or maybe do this first. If the commode donut isn't seated properly then it could be possible air can come through without leaking water. The commode flush valve also has a seal that should help to prevent odors from the tank.

Mind you these are just suggestions that I haven't seen in other posts that I hope will help and are from my experiences in the HVAC field and long time RVer.

One other thought is if you are running the bathroom fan while flushing this too can pull the smell up from the tank into the trailer.

For the most part we just keep a can of air freshener in the bathroom and give a squirt or two after use. Seems to keep the smell down for the most part.

John

Pull down the inside trim for the A/C, check to see if the attic is completley sealed off from the A/C return air. If not, get some foil tape and start sealing. If allowed to be open to the A/C return, the A/C will draw air from the attic, the attic will draw sewer gas from around the vents ( the sewer vents are not sealed to the roof to allow movement in the pipe from the tank expanding ).