Sticky Dometic 310 toilet valve

Shut off the water. Let all water run from tank. Spray with silicone. Open and close valve...spray again....let dry.
Then turn water back on.
I do this every month or so. Be sure the rubber seal is clean. You can put on some rubber gloves and feel the seal. It should be smooth. If it is rough, then replace. The Kit, Flush Ball Seal is Sku 9108559082. Mfg. Number 385311658.

joelc wrote:
Shut off the water. Let all water run from tank. Spray with silicone. Open and close valve...spray again....let dry.
Then turn water back on.
I do this every month or so. Be sure the rubber seal is clean. You can put on some rubber gloves and feel the seal. It should be smooth. If it is rough, then replace. The Kit, Flush Ball Seal is Sku 9108559082. Mfg. Number 385311658.

He's talking about the water valve...

Grit Dog...Then you come up with some valuable information instead of correcting others.

vicmitch wrote:
Hello,

Been having trouble with my Dometic 310 toilet intake water valve sticking open partially wasting precious water into the black tank, just like to know if how common this, just had the old valve replaced, the new one did not work any better, does Thetford toilet valves have the same problem.

Thanks

No the fill valve should not leak. If you replaced the valve with a new one and it still leaks then either you have some foreign matter in the valve that is causing it to be partially open. Or your water pressure is too high and forcing water past the valve.

Does the leak happen only when hooked up to shore water? Or does it also leak when running the fresh water tank and water pump?

The toilet intake valve leaks with the on board pump pressure as well as our house well pump pressure of 60 lbs, doesn’t appear to be a way to take the valve apart to see what the problem really is either. I sanitized and flushed the camper water system, putting in another new valve as well as a cut off valve in the line as a backup for the problem, on the new valve I can see a screen in intake so what ever gets by the screen would be pretty fine.

So the replacement valve doesn't work any better and it still leaks under pump pressure. It sounds like there is some kind of debris in the water system that is getting stuck in the valve. Either that or when you installed the new valve you did not get it seated correctly.
since I'm guessing you have debris in the valve I doubt a Thetford would work any better.

Do you possibly have enough hose length to disconnect the fill pipe from the valve, wrap it in a coffee filter and put it in a dry bucket. Have someone turn on the water pump while you hold the hose end in the bucket. Count to 30 and turn the pump back off. Now check the coffee filter and see if there is debris stuck in it.

Reading your last reply again, if there is a really fine screen on the intake of the fill valve I would suspect there is something holding the valve partially open. Is the flush a lever or a foot pedal?

vicmitch wrote:
Hello,

Been having trouble with my Dometic 310 toilet intake water valve sticking open partially wasting precious water into the black tank, just like to know if how common this, just had the old valve replaced, the new one did not work any better, does Thetford toilet valves have the same problem.

Thanks

So are you referring to the water that sits in the bowl?
If that is what you are referring to it is normal it forms not only rubber seal, but also a water seal.

• Mfr. Part No.: 385311641 Water Valve Kit
• Fits 300, 310, and 320 Series Dometic Toilets

You can find it at many outlets for different prices. Look it up on the internet.