R31 Aft Toilet Backwash

[Ken W]

So, an indelicate problem; the aft toilet in my 2017 R31 gets "backwash" from the holding tank. After flushing, there's gurgling and bubbles and holding tank contents flow into the bowl. Also, when the holding tank has filled a bit, but is not yet full, the contents appear in the aft toilet, especially if the boat has been pitching and rolling much. I think the toilet is a "Raritan". Does is sound like the problem lies with the toilet, or is there a non-functioning check valve somewhere?

 

[Wee Venture]

Could your vent be plugged? If you flush and the vent is plugged, the air pressure in the tank has no way to equalize except by pushing the residual fluid back through the pipes from whence it came.

John

 

[it4llc]

I had a similar problem on our C28, although we've got a SeaEra Toilet. It ended up being the joker valve - https://www.westmarine.com/buy/raritan--atlantis-sea-era-toilets-joker-valve--257092. Once I replaced that, it was good as new. The 'manual' for the toilet I believe has a parts diagram so you can see how to replace it, and I think there was a prior post on Tugnuts on how to do this. Basically though, run a LOT of water through to make sure everything is as clean as possible (and pump out and rinse the holding tank, and flush some more water...), and get a bunch of rags ready. On our toilet, you remove 4 screws, one of which required a smaller longer screwdriver and entailed borrowing said screwdriver from the marina, pull the mounting bracket off, replace the joker valve, and reattach the mounting plate. Other than having to run up to the marina office, it was one of the easier repairs I've done on our boat.