Converting a Stationary RV to a Residential Toilet

[DaviDINO]

What advice can anyone offer for removing RV toilet on a stationary setup to install a standard (round seat, due to space limitation) toilet with water cutoff? This unit no longer travels; it is piped to septic tank.

 

[Greg Brannon]

Do you mean to replace it with a household-style gravity flush toilet with the tank on the back? If so, have you seen others with this mod? When you say space limitation, how much space do you have? What make/model RV toilet do you have now? Why do you want to replace it?

Greg.

 

[DaviDINO]

Yes, a gravity fed flush toilet is the goal. RV toilet pump system is broken. This 5th wheel is now set to stay under cover as mini-home. "Knee" space is limited in RV bathroom.
THANKS for your reply. Any advice?

 

[Greg Brannon]

I've seen this question asked before, and I don't recall there being a satisfactory solution - at least none reported. Based on that plus the small amount of space you have for a mod, I recommend fixing what you have. Can you describe what you mean by "toilet pump system?" Is there a volunteer handyman nearby that could assess what's wrong with what you have and advise on fixes?

I may be entirely wrong on the best direction, so wait for others more wise to chime in.

Best of luck!

Greg.

 

[Gary RV_Wizard]

The "knee space" is likely to be a deal breaker. A residential toilet needs to stand several inches from the wall to allow room for the flush tank, plus the drain hole is several more inches in front of that. There are hidden "in-wall" tanks available, but RV divider walls are rarely thick enough to be much benefit - might gain just 1.5"-2".

The rest of it is removing the RV's waste tank and running a 3" or 4" diameter waste drain at a slight down angle from the RV to the join the septic feed (which is may be 4"). The toilet drain line needs a constant down-angle of 1/4"/foot to assure that solids & paper drain well.

 

[DutchmenSport]

Well, one way to get around the extra depth of the attached water tank is to install a residential toilet, maybe something like this:

 

[Kirk]

Read the post #5 very carefully. The point is that it simply will not work without major modifications to the plumbing and also to the floor of your RV.

 

[Gary RV_Wizard]

Those diagrams are helpful but a bit more daunting than need be. The waste tank is already vented to the roof, but you have to retain that vent when you remove the tank. It has to hook into the waste line somewhere, so requires some creativity. You don't need a copper pipe for fresh water - the existing pex or pvc flush filler line will do nicely.

You mentioned an RV toilet pump. Is the existing toilet a macerator (pump) type? And are there two toilets? Maybe one a gravity drop and the other a macerator pump type?

 

[Kittykamper]

Well, one way to get around the extra depth of the attached water tank is to install a residential toilet, maybe something like this:

Wow!!! That bathroom is GIGANTIC!!!!

 

[DaviDINO]

Thanks for responding, Gary. Current single commode is a 2 step petal Thetford toilet (half press to fill, full press to flush). Some linkage from petal to valve system has broken. Have a handyman who claims to have converted several RV toilets to standard 12" setback tank unit. If this works, I hope to be able to post photos.

 

[gwinger]

Read the post #5 very carefully. The point is that it simply will not work without major modifications to the plumbing and also to the floor of your RV.
View attachment 2481194

There are residential toilets that have a 10 inch rough in. Probably still to far for the space.
Another problem may be the floor flange. Most residential toilets utilize a 4 inch pipe flange.

 

[Utclmjmpr]

I was wondering if a 90 degree turning of the toilet would held with room?.. My RV toilet was too low to be comfortable,, so I built a 4 inch pedestal and raised mine with excellent results

 

[gwinger]

I was wondering if a 90 degree turning of the toilet would held with room?.. My RV toilet was too low to be comfortable,, so I built a 4 inch pedestal and raised mine with excellent results

Still the problem with the size of the flange and pipe.
Plus, turning the toilet would put the side very close to the wall.
The floor would have to be rebuilt and plumbing replaced.

 

[bigbAZ]

Still the problem with the size of the flange and pipe.

There's a solution for that, and it also gives you a bit of offset from the wall. Available in both PVC and ABS.

https://www.homedepot.com/pep/ProPlus-3-in-x-4-in-PVC-Schedule-40-Offset-Closet-Flange-94848/341984515?g_store=&source=shoppingads&locale=en-US&fp=ggl&pla=&mtc=SHOPPING-BF-CDP-GGL-D26P-026_001_PIPE_FITTING-NA-NA-NA-PMAX-NA-NA-NA-NA-NBR-NA-NA-NEW-_PMAXTEST&cm_mmc=SHOPPING-BF-CDP-GGL-D26P-026_001_PIPE_FITTING-NA-NA-NA-PMAX-NA-NA-NA-NA-NBR-NA-NA-NEW-_PMAXTEST-17697557984--

 

[bigbAZ]

There are also corner toilets, if "knee" room is tight. You can order a 10" bowl and use the offset to gain 1.5-3" RI

 

[Kirk]

If this works, I hope to be able to post photos.

If you get it done, please do share the information with us. as well as just how it was done and how you like the results.

 

[Gary RV_Wizard]

Another problem may be the floor flange. Most residential toilets utilize a 4 inch pipe flange.

He will have to replace the drain plumbing under the floor anyway, and probably re-position the flange as well, so a new floor flange won't be an issue.

 

[gwinger]

He will have to replace the drain plumbing under the floor anyway, and probably re-position the flange as well, so a new floor flange won't be an issue.

And possibly remove the black tank depending on how the toilet was plumbed.
Some drop directly into the tank.

 

[Gary RV_Wizard]

And possibly remove the black tank depending on how the toilet was plumbed.
Some drop directly into the tank.

No "possibly" about it. The tank has to go.

Gravity-drop directly to the tank is the standard means of plumbing an RV toilet. Toilets located elsewhere than over the black tank have to be macerator types that grind up the solids & paper and pump the slurry to the tank. But it makes no difference in this modification because the black tank is not and can not be used with a residential-style tank flush toilet. It gets removed regardless.