Technique Fixes Thetford RV Toilet Waste Valve Leak

By Guest Author: Allen W. Inks
We have a Thetford Aurora toilet, with a "waste" valve that slides to one side when you step on the pedal to dump the contents of the toilet bowl (there's a second water pedal to add water without opening the outlet valve). Many RV toilets operate in a similar manner.

The problem was that the waste valve wouldn't always close completely. I tried lubricants, cleaning the groove into which the moving valve part seats with a tool made from a coat hanger (to get rid of, for example, toilet paper that might have gotten caught when the valve shut too soon). Spraying silicon lube on the top seemed to help a bit, sometimes, for a while. But inevitably, the toilet would begin to stick open just a crack - just enough for water to drain, and odor to leak in. I even replaced the who valve assembly. Which worked for about a week (boy, was I disappointed when it stuck open the first time after spending around $100 on repair parts (no labor).

Ok, so that's the background...what's the solution I found that works?

It's technique! Technique for stepping on the toilet pedals. What we used to do is step on the pedal to open the waste valve, hold it open 'till all was flushed, then raise our foot to close the valve. Nice and gentle on the equipment, and quiet. And allowed the valve to stick open part way.

What we do now is step on the pedal to open the valve, and then, when the contents have been flushed, pull our foot toward us, slipping off the fully depressed pedal. The spring quickly shuts the valve with a bang - and the valve moves past all the little sticky intermediate friction points to fully shut the toilet. That's all there is to it: slide your foot off the pedal, rather than lifting it off - thus allowing the valve to move much more quickly (and thus with more inertia) to the closed position.

Note that because the levers for the pedals for the waste valve and the water addition valve are right next to each other, it seems that friction can cause the waste valve to slightly open when adding water. However, by using the "slide don't lift" technique for releasing the water valve, the waste valve seems to return to the fully closed position if it indeed was opened at all.

Hope this helps someone.