Thetford 31650 Toilet Leak in 400

manyman297

So I think I have a leak in the main valve of our toilet. I’m on the road so can’t dig into anything yet but I see drops of water on the water inlet of the valve. Anybody ever have to replace that valve?

slmarchap

Hi manyman297!  Hope you're having a great time on the road! 

On our recent 2 week getaway, we also noticed a leak behind the Thetford.  See picture.  We have a 2020 400BL.  The fresh water leak comes in just above the black piece you see.  Is it the same for you?  Upon looking at the owner's manual, it looks like the #8 Water Module/Water Valve.  Ours leaks when the water pump is turned on and there is pressure in the lines.  It REALLY leaks when we flush the toilet.  Thankfully I had installed the "hack", a manual shut off valve in the water line leading to the toilet, suggested on another thread. 
This allowed us to use the water in all other areas in the camper, but we needed to manually pour water in to the toilet bowl and "flush" without using the water line to the Thetford.  Inconvenient, but we were able to get by just fine throughout our trip.

I have sent NuCamp a request to verify the model as I can't find any model number on the user manual documentation nor on the toilet itself.  I believe that it's an Aqua-Magic V with pedal flush.  It's a tight squeeze back there and I fear that removing the toilet to replace the valve is in my future! 😒
Any input is welcome!!! 

manyman297

@slmarchap So once we returned from our trip I ran a few tests and I couldn't get the toilet to leak when on the water pump...but on city water with super low water pressure (like 30psi) it would leak when flushing the toilet. 
 
I'm not sure if low water pressure can cause leaks but this toilet AND the kitchen sink faucet were both leaking on that trip which found us always connected to city water with a pressure regulator. Once I put them both on the pump the leaks stopped. 

Now granted the leaks were more like very slow drips but they were leaking nonetheless. 

Luckily if it leaks again it appears the valve replacement isn't very difficult to do (even with the toilet seated) and the part is $24. We're camping using the pump this coming weekend so we'll see if it does leak again. 

Here's the valve part for our toilet which I believe is the same as what's in the 2020 400:

https://www.amazon.com/gp/product/B002UC1AYQ/ref=ox_sc_saved_title_2?smid=ATVPDKIKX0DER&psc=1

slmarchap

@manyman297 Thanks for the link.  I'll check it out!  I'm hoping for a quick fix. 

Regarding your issue, good luck!  It seems strange that the pipes leak/drip when at low pressure connected to city water.  Just a shot in the dark....perhaps your 30psi regulator is not calibrated correctly or broken? 

Happy travels!

manyman297

@slmarchap The pressure issue sent me down a rabbit hole where I realized that the standard 50psi regulators don't regulate all pressure to 50psi...it's a sliding scale. I forget the percentage but let's say you have 60psi coming from the spigot. That doesn't come out of the regulator at 50psi...it's more like 30psi. We had terrible pressure in the kitchen sink (just installed the faucet last year and hadn't yet used it on city water until this last trip) and realized the fixed 50psi regulator was pushing the pressure down to 25-30psi. I ended up buying an adjustable regulator, adjusted it to 50psi and didn't have leaks at the faucet or toilet. So? Not sure but all signs point to low pressure causing these leaks which is peculiar. 

slmarchap

@manyman297
A quick follow-up...I just ordered the part from your link and I found a GREAT YouTube video of how to remove the old and install the new valve.  
Thanks again and best of luck with your water pressure/leak issue!  Sorry that I couldn't help you as much as you helped me. 😔

manyman297

@slmarchap Great news! No worries. Worst case I install the new valve which doesn’t look too difficult. 

slmarchap

For anyone who has the same leaky valve, here is a YouTube video with AWESOME step by step instructions.  This gentleman had the Aqua Magic V Thetford toilet in his Casita.  The valve started leaking ABOVE the black seal, same as ours.  It's not something we can fix, but rather a replacement exercise. I used a mirror and some very short handled tools to complete the installation.  NO need to pull the whole toilet!  Part info:  Thetford 31705 Water Module Replacement Package.  I ordered it on Amazon.
For the video, search YouTube:

Casita - Toilet Valve Replacement by RV Adventures

https://www.youtube.com/watch?v=_EuzRHUMvuM&list=PLsLdIIxt-ODq5TWB2PLSZLLy4A14ELScP

manyman297

Wanted to update my leaky toilet valve issue. What I thought was a low pressure issue turns out not to be true. The valve is indeed leaking regardless of pressure. It’s a slow, inconsistent leak but it is leaking. I’ll replace it next season.