I accessed the P-trap on the drain from the shower and drilled a hole for the fitting you see in the picture. Then I tapped the hole, put ABS cement on the fitting and screwed it in the hole. I then added a short piece of hose to a shut-off valve which runs out to a hose under the camper. Now if I want to shower, but don't want to fill the black water tank, I open the valve and the shower water can run into a bucket. Close the shut-off and the shower drains into the black water tank.

 

I've never heard of an RV manufacturer plumbing the shower into the black tank...
Rob

 

Really? It's pretty common. Many small TCs do not have enough space for separate black and gray water holding tanks. The brochures say they have a gray and black water tank, which they do, but only the galley sink drains into the gray water tank. Everything else goes into the black water tank.

If you want a low profile and minimum weigh there is not room for tanks between the camper floor and the truck bed unless you are going to raise the camper up off the bed. And plenty of folks who "overland" place maximum importance on weight and height and almost no importance at all like having a shower or even a commode. That is part of the reason for the growing popularity of the cassette toilets. I just reversed the idea as the way my Hallmark is configured putting in a cassette toilet was just not possible without reconstructing the entire bath.

 

OK - my mind didn't even go to TCs. Say the word "RV" and I automatically think larger towables and class As, since those are the people we are around.
Rob

 

Yeah, they're not on most folks' radar screens as they make up a pretty small part of the RV market.

 

We are in the Slide-in/Truck Camper forum right?!

 

That is a great idea, thanks for posting. Although my Lance shower drains into the grey tank, But I could still divert it like you did.

 

Just used it last week for the first time in the National Park. Worked great.

 

I haven't looked under the covers of my toy hauler to see if the shower drains into the black or gray tank. Is it mainly on the truck campers that it does that?

 

Just some truck campers although in the past many manufacturers had the vanity sink empty into the black water tank to insure there was enough liquid to carry the waste out of the tank. That is less common now that so many campers have separate closets for the commode.

 

Our 2015 Host Mammoth TC has only the toilet and bathroom sink drain into the black tank (the tank, toilet, and sink are all in the driver side slide). The shower (fixed) and kitchen sink (in passenger slide) drain into the gray tank (fixed in basement). If our shower did drain into the black tank, I'd duplicate your idea - it's good thinking.

 

Obviously the idea is pretty simple. What we were finding is whenever both my wife and I showered we had a full black water tank very quickly and we did not want to have to break camp to go dump. This way with a 14 gallon black water tank, the shower empties into a 7 gallon jug which we can dump in a comode or gray water basin in the National forest. That leaves our black water tank for just the other stuff and if there are restrooms without showers, we can just refill our fresh water tank using another jug and really lengthen our stay. Close the shut-off for the bypass and everything is just as it was.

 

 

 

Just convenience. It was much easier to drill this particular trap where I did and so far gas has never been a problem. I doubt when I drain it, I am completely emptying the trap as i shut off me spigot as soon as the flow starts to slow leaving some in the trap. Wife and I take turns showering. When we are using the drain, we conserve water so we use maybe a gallon of water. Our drain also has a plug so the shower drain can be closed. I suspect that helps.

One option some folks do is to disconnect the trap and plug the black water tank side and use a plug in the shower side drilled for the spigot. I choose not to do that as when we are camped in a campground with hookups, I wanted to be able to use the hookups in the campground.

There are always lots of ways to do something. This one works. If it proves to be a problem I'll redo it. Traps are cheap and once I decided what I wanted to do. the whole shebang took only minutes. Maybe your idea is better. Give it a try and report back.

One real downside to the manufacturer's setup is if the black water tank fills, it will back up in the shower through the shower trap. That is also a danger here. If the black tank is full and you open the spigot, you will be draining black water with the gray, until the level srops - yuck!