Community Forums

goofyziggy · 01-28-2025, 01:32 PM

Fellow RV'ers: Im battling with a ~6yr old Dometic 320 toilet's ball that is not shutting all the way on its own, seems lose or not tighly coupled to the pedal.

Troubleshooting done: I've cleaned the lime and calcium deposits off the ball, replaced the gasket, lubed the s**t out of it with plumber's grease (not petroleum jelly!) and still the bowl will not hold water. When the toilet ball is closed, it can be easily moved back & forth with your finger as if it's not "locked in" nor snapped into place. Also when depressing the pedal one can see the ball move in jerky motions, not one smooth motion, as if the toilet ball is not tightly coupled / linked to the pedal assembly. Important to note that online research seems to confirm there is nothing on the pedal or its springs that can be replaced or updated on a Dometic 320. It seems the rv toilet pedal cannot be disassembled, nothing.

All in all, the rv toilet ball has sufficient movement or "play" on it that Im starting to wonder if I have to replace the whole toilet to fix that one part - which would be a very sad state of affairs.

This is very similar to another post from 2023:
https://www.irv2.com/forums/f258/dom...es-604827.html

My question is whether the whole toilet needs to be repaired, or what else can be done to ensure the toilet ball is tightly coupled to the pedal so it closes (snaps shut) with some force - and thus holds water. Thanks for any advice or help.

Jim_HiTek · 01-29-2025, 10:25 AM

Wow, I dug deep on that model and sure enough, they don't show any replacement parts for the spring operator, or the ball or show how it's attached or adjusted.

I know that I'd give them a call and ask what's up: 330-439-5550

If it's true that it's non-serviceable (and this drawing doesn't show those parts: Dometic 320) I would strongly consider changing toilets to one that is easier to service. Like the Dometic 510+, I believe there is a tall one in that line. Entire toilet is available at Amazon. Or their 310 series. Parts are readily available at eBay and Amazon plus everything is serviceable.

There is this though: If the toilet does not hold water in the bowl, refer to “Troubleshooting” on page 15 before you replace the flush ball seal.

That's in this document: Dometic too

Good luck.

goofyziggy · 01-30-2025, 09:21 AM

Hi Jim! Thanks for validating what I was seeing. I think i've patched it up (for now), details below, but also thanks for recommending possible replacement toilets.

Im not there yet, but I appreciate pointing me to the Dometic 510 - wow, nice toilet! It's the most expensive RV toilet i've seen, and the only one that says it's made for FULL TIMERS right on the title. It's called:

<a href=https://www.etrailer.com/RV-Toilets/Dometic/DOM29FR.html> Dometic 510 Full-Timer RV Toilet - Standard Height - Elongated Seat - White Ceramic
Part Number: DOM29FR </a>

Funny enough the toilet itself cannot be found on Amazon, but its parts are there....weird.... probably the price? The Etrailer.com store seems to have it available, however, go figure....

The patch/fix: i put on the disposable gloves and got in there, took the seal out and looked more closely at the ball and its mechanism from above. Boy, it's gross in there. Anyway, it's all plastic which makes you wonder what's the expected lifecycle on a Dometic toilet. By touching the ball i am able to confirm it just moves on its own, has about 1-2" of play, easy to move it too, doesnt take much. It's basically lose or not tightly coupled to the pedal. That being said, the rubber seal itself was 1yr old, and it had quite a bit of scale/calcium deposits from the hard water on it, surely that didnt help make a tight seal. Also the plastic ball had similar calcium deposits on it which were not visible until the rubber seal was removed. So I grabbed a caulk tool and gently scratched those hard calcium deposits off (again, this was gross, it's calcium mixed with toilet "stuff"). Made sure not to scratch the plastic itself, just enough to get those deposits off. Also hold the tool tight cuz if it drops i'd be hosed. Got it all clean, installed a new seal gasket, lubed the heck out of it with plumber's grease, and done.

Now the ball still shuts about the same as before, it does not close all the way in (because of its lose/play), but it did seal sufficiently to hold water!! Such a relief. From what I can gather this assembly may have 1-2 yrs left on this toilet if I baby it, keep cleaning and lubing the ball & seal. Eventually a new one will be needed, and I hope I can afford the Dometic 510 by then because it looks like the nicest of the bunch.

Thanks for the help & advice Jim!!!

Iceclimber · 02-01-2025, 01:41 PM

Might take at look at the 310, it's kind of a steal. I figure 5 or so years of full time use is fair and if it breaks I am not taking it apart. I froze one of these (totally my fault) and they sent me a whole new one, no questions asked. Fan for life.

https://www.amazon.com/Dometic-310-S...40&sr=8-7&th=1

Jim_HiTek · 02-08-2025, 10:19 AM

One of the Troubleshooting Guide suggestions if it leaks by the ball for my 510+ is to allow the pedal to 'snap' back when you flush. Dunno if you're doing that already but that's what my guide says to do. I've been doing that for quite a while now and it doesn't seem to damage the spring assembly. Strange suggestion but it works.

Tony Ramirez · 02-08-2025, 10:53 AM

Sometimes toilet paper will get lodged in the groove that the "ball" slides into, preventing it from sealing. I've had to bend a coat hanger & "hook out" some TP before.

Always pleasurable dealing with the toilets.