Odor from island sink

[TrevorL]

I have a 2015 PrimeTime Crusader 294RTL

I am getting odor out of the island sink when left for a few weeks or after hauling the trailer.

I am guessing what is occurring is that the trap is drying out and I am getting odor from the grey tank. When I add water to drain the smell stops.

Any thoughts on how to stop the odor from occurring

 

[Reverse_snowbird]

Do you have grey water treatment in the tank?
If you put a stopper in the sink that should help keep the trap from drying out.

 

[TrevorL]

Do you have grey water treatment in the tank?
If you put a stopper in the sink that should help keep the trap from drying out.

Simple solutions are the best!! Why didn’t I think about using a stopper in both sinks while traveling. Currently in BC. Will try this on the return home.

I’m not familiar with grey tank treatment solution - only black tank. Is this something similar?

-Trevor

 

[Reverse_snowbird]

I’m not familiar with grey tank treatment solution - only black tank. Is this something similar?
-Trevor

Yes. You can pick up rv treatment that treats both grey and black water tanks either online or at any place that sells rv supplies. They also make separate grey water tank treatments.

 

[TrevorL]

Yes. You can pick up rv treatment that treats both grey and black water tanks either online or at any place that sells rv supplies. They also make separate grey water tank treatments.

Thank you for the insights.

I’ve been trying to figure out how to clean the tanks for a while. Our unit is new to is, but I do not know it’s use history.

I just came across this website with a informative (and entertaining) YouTube video.

https://www.happycampers.store/blog/cleaning-your-rv-gray-water-tank-to-prevent-odors-and-clogs/#:~:text=One%20of%20the%20primary%20causes,%2C%20releasing%20foul%2Dsmelling%20gases.

I have used Happy Camper (aka Classic Camper) for the black tank. I will be cleaning the grey tank in the VERY near future. But putting a stopper in both sinks in the short term.

-Trevor

 

[jimmoore13]

Traps inevitably dry out. But not all traps are siphoned out or blown out while going down the road. Aerodynamics are more complex than one might think. I suggest you check your roof vents to make sure their caps are in place properly and not partially blocked or otherwise obstructed.

It's possible for the grey tank roof vent to allow passing air to create a suction or positive pressure in the grey tank that then sucks or pushes water out of the traps. While plugging the sink drains will minimize this, the "instavents" under sink cabinets can still allow water to be sucked out of the traps.

This is a pretty obscure thing to consider, but you might be surprised to see a missing cap...or otherwise dislodged vent cap on your roof. Also consider that unpredictable aerodynamic influences from other items on your roof might be contributing to the problem. If this "dry trap" phenomenon has been happening since you got the rig, the rooftop layout of all the bits and pieces above the roof might contribute to the problem. There are several different designs for these caps that you might consider if yours is intact and "should" be working properly but isn't.

Freakish weather conditions with high winds blowing across the roof vents in homes can cause this to happen, so dragging your plumbing down the road at 65 MPH presents quite a challenge for drain plumbing.

 

[RobbieH]

I found out the hard way with my last coach that the P trap dries out to the laundry washer and that it has to be used occasionally. No way to put a cap on that!

I use this for both my black and gray tanks. It works great.
https://kleentank.com/throw-away-your-rv-tank-additive-use-this-instead/

 

[Willhound]

A little squirt of Dawn dishwashing liquid in the tanks from time to time and sloshing down the road adds some scent and helps clean grease out of the tanks....

 

[TrevorL]

This makes a lot of sense to me.

Today I am dealing with a slow drain (blockage). In the galley sink. As it is an Island I suspect the one way valve has failed. I am also suspecting that a secodary issue of the pipes not being cut and pieces together properly is reaulting an a anti-gravity slope for the drain - resuling in a vapor lock.

Don’t have the resources to fix this today, so will work with it.

Traps inevitably dry out. But not all traps are siphoned out or blown out while going down the road. Aerodynamics are more complex than one might think. I suggest you check your roof vents to make sure their caps are in place properly and not partially blocked or otherwise obstructed.

It's possible for the grey tank roof vent to allow passing air to create a suction or positive pressure in the grey tank that then sucks or pushes water out of the traps. While plugging the sink drains will minimize this, the "instavents" under sink cabinets can still allow water to be sucked out of the traps.

This is a pretty obscure thing to consider, but you might be surprised to see a missing cap...or otherwise dislodged vent cap on your roof. Also consider that unpredictable aerodynamic influences from other items on your roof might be contributing to the problem. If this "dry trap" phenomenon has been happening since you got the rig, the rooftop layout of all the bits and pieces above the roof might contribute to the problem. There are several different designs for these caps that you might consider if yours is intact and "should" be working properly but isn't.

Freakish weather conditions with high winds blowing across the roof vents in homes can cause this to happen, so dragging your plumbing down the road at 65 MPH presents quite a challenge for drain plumbing.

 

[Bob K4TAX]

I have a 2015 PrimeTime Crusader 294RTL

I am getting odor out of the island sink when left for a few weeks or after hauling the trailer.

I am guessing what is occurring is that the trap is drying out and I am getting odor from the grey tank. When I add water to drain the smell stops.

Any thoughts on how to stop the odor from occurring

It does appear there is an air admittance valve on the line above the sweep (T) going through the floor. These are supposed to be closed, but open when air is needed into the line. Could be stuck in the open position. Either replace it or give it a good whack. Maybe some trash is lodged inside. Of course, cleaning the tanks is always a good idea.

Don't label me crazy but...... I have seen a preferably unused condom placed over these valves. Of course, that may cause the sink to gurgle when draining. But it stops the stench.

Bob

 

[TrevorL]

It’s interesting that you provide me with this information today. This morning my galley island double sink stopped draining. Nothing blocking the line. The moment I took the air check valve from the pipe the sinks drained.

It’s looking like I need a new check valve. I played with it, but can’t seem to get it operating properly.

I think I also need to adjust the plumbing lines so that they have a downward slope. Things seem to slightly slope upwards from the P-trap to the main line to the grey tank.

-Trevor

It does appear there is an air admittance valve on the line above the sweep (T) going through the floor. These are supposed to be closed, but open when air is needed into the line. Could be stuck in the open position. Either replace it or give it a good whack. Maybe some trash is lodged inside. Of course, cleaning the tanks is always a good idea.

Don't label me crazy but...... I have seen a preferably unused condom placed over these valves. Of course, that may cause the sink to gurgle when draining. But it stops the stench.

Bob

 

[jimmoore13]

<<SNIP>>
Don't label me crazy but...... I have seen a preferably unused condom placed over these valves. Of course, that may cause the sink to gurgle when draining. But it stops the stench.

Bob

Not crazy at all.
Practicing "safe drainage" is always important. Especially the "preferably unused" part.
You get the "best comment" award for the day!!

 

[TrevorL]

[sigh]

2024 09 27 UPDATE

So…

When we bought I asked several times if there was only one grey tank and one black tank as there were sensors buttons for two grey tanks and two black tanks.

I was assured by the salesman that there were only ibe of each tank. We paid $1000 for the service department to do a stem to stern inspection and to do a full mechanical walk-through with us. I again asked about multiple tanks, and was assured that there was only one of each as there were only a total of two tank release valves on the trailer.

I sent a fish wire up the exterior sewer pipe - nothing.

I sent a fish pipe down the kitchen sonk - tank full of water.

I crawled under the trailer and strategically opened the underside coroplaat seal. I found three tanks. Two sounding empty. One clearly full. I followed the full tank piping and found a release handle hidden up high under the trailer. I opened that up and water gushed out. Turns out the galley has a separate grey tank from the bathroom grey tank.

Water back-up problem solved.

As for the smell I am going to
1) clean all the tanks with Happy Camper Extreme clean in the spring. I have water enough videos and read enough testimonials to be convinced this is a good product to use to clean tanks
2) install a waterless p-trap under the galley sink. This way i know that a good air seal will occur and I don’t have to worry about the standard p-Trap drying out.

As for the dealership, their lack of awareness regarding the trailer further reinforces that I will stop going to them for service/support. We have had to take the trailer back to them multiple time as the stem-to-stern inspection/repair was not completed. We found a myriad of issue that they should have caught. In fact, the day we were to pick it up after the completed the stem-to-stern we refused the trailer as they had failed to do the work required (after having two months to complete the work).

Long run the smell was indicative of other underlying issues.

 

[Reverse_snowbird]

Thanks for the update. Glad you solved the problem.
It sounds like changing dealers might be a good idea. The fact that they couldn't find the third tank and dump valve doesn't reflect well on their knowledge or repair skills.


If you could post a picture or description of where you found the third dump handle, it might help someone else in the future.

 

[Chuck_S]

Glad you found your other grey tank!

Tighten the sink stoppers before towing (driving) and when parked for any length of time. No sewer gasses can get in with them closed.

-- Chuck

 

[TrevorL]

Here's the handle

It took me a bit to get back, but here's a couple of photos of where the second (Galley) Grey Tank Release valve is located. I took the photos while winterizing my unit, so please ignore the exterior shower hose hanging down.

The Galley tank release handle is tucked up over the sewer drain.

-Trevor