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Toilet Fills with Water Pump On

Lakejumper
Explorer
Explorer
Help, we’re boondocking in the Desert. I have a Thetford Style II that is filling up quickly on its own when the water pump is on! Could this be the flushing mechanism in the back of the toilet or something else?
Lakejumper

2016 Winnebago Vista LX 30T
2012 Chevy Equinox
12 REPLIES 12

Veebyes
Explorer II
Explorer II
On my 'to do' list this spring during the annual boatyard refit. Mine developed an annoying intermittent leak last year. Took the foot valve apart & put it back together a few times as we were mid trip & not anywhere to get a new one.

Cheap & easy part.
Boat: 32' 1996 Albin 32+2, single Cummins 315hp
40+ night per year overnighter

2007 Alpenlite 34RLR
2006 Chevy 3500 LT, CC,LB 6.6L Diesel

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gtnsmlr
Explorer
Explorer
Over the years of full timing, I've replaced all the parts on mine a number of times. the water valve, if needed is a simple fix. I've noticed that the valve Is prone to leakage if the water pressure is low, give that a check. If you have access to the pedal side you can replace the valve parts without removing the toilet but for the first time pull the toilet, getting the peddle back on is a chore and best done o n the table with a beer. I actually like the style ll, you can rebuild all the moving parts in 15 minutes once you get it out.
The older we get, the faster we go

wnjj
Explorer II
Explorer II
Bobbo wrote:
That would drain the toilet, not fill it.

Must not have been the case. Likely the blade is connected to the water valve so that if it doesn’t travel far enough shut the water continues to run.

Bobbo
Explorer II
Explorer II
That would drain the toilet, not fill it.
Bobbo and Lin
2017 F-150 XLT 4x4 SuperCab w/Max Tow Package 3.5l EcoBoost V6
2017 Airstream Flying Cloud 23FB

Lakejumper
Explorer
Explorer
Well. The “fix” was cleaning the blade at the bottom of the toilet. It wasn’t closing all of the way. Now it’s working fine.
Lakejumper

2016 Winnebago Vista LX 30T
2012 Chevy Equinox

Traver8
Explorer
Explorer
I had a similar situation and found that the valve was fine but the foot pedal had begun to break where the "stop" is which let the valve remain slightly open. I managed to improve the pedal with a small block of wood to provide extra support for that area. Has been fine for several years now. You might want to pop the pedal off and take a good look at it.

WILDEBILL308
Explorer II
Explorer II
I had this happen on my last RV. It is the water valve that you activate with the foot control/flush peddle. Look at the side of the toilet. Easy fix You can get one at most camping part stores and if desperate at Camping world.
Bill
2008 Newmar Mountain Aire
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ALLISON 4000 MH TRANSMISSION
TOWING 2014 HONDA CRV With Blue Ox tow bar
A man who carries a cat by the tail learns something he can learn in no other way.
-Mark Twain

wa8yxm
Explorer III
Explorer III
Lakejumper wrote:
Could this be the flushing mechanism in the back of the toilet or something else?


There are two suspects and yes that is #1
#2 is the linkages that operate the valve sticking and that's easy to eliminate by manually checking the valve to insure it's in the "Closed" position.

NOTE. very easy to replace the valve.
Home was where I park it. but alas the.
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Lakejumper
Explorer
Explorer
Thank you all for your quick responses and good suggestions! We did try snapping the flush pedal a couple of times. We will look to install a shut off or plug the water line tomorrow as a temporary fix.
Lakejumper

2016 Winnebago Vista LX 30T
2012 Chevy Equinox

ItsyRV
Explorer
Explorer
It could be a worn or damaged valve, OR it could be some schmutz got stuck in the valve causing it to not fully close. Try rapid opening and closing to see if the seal reseals. Try turning off the pressure and drain down the line a bit to see if that dislodges any gunk. You can even shut off the water, disconnect the line and blow some low pressure air into the toilet while working the valve to see if that helps.

A couple years back I had a sticking valve. I shut off the water, removed the line and squirted some liquid dishwashing soap into the inlet while opening and closing the valve. After reconnecting, no more stuck open valve (I did replace it anyways later that year as a precaution).

if those don't do it, you'll need to make a temp fix like MFL or gwalter suggested.
1994 Itasca SunDancer 21RB - Chevy G-30 chassis.

gwalter
Explorer III
Explorer III
The valve on my toilet did something similar. I temporarily fixed it by installing a sharkbite shutoff in the line behind the toilet. Then you can fill the toilet as needed by opening and closing the valve without disrupting the water supply elsewhere.
2010 Ram 3500 Laramie
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MFL
Nomad II
Nomad II
Is it filling to overflowing, or just a half gallon or less? If it continues to fill/overflow, I would suspect the mechanism is sticking or broken.

Easy thing to try, operate flush handle/pedal and let it snap closed. Worst case, you may need to plug supply line to toilet, and use other water source for a manual flush.

Is there a handy guy camping near you, that may be willing to check the valve serving the toilet?

Jerry