Dometic 310 Flushing issue

[jvink]

Hey All,

Can't seem to find my situation in the search, maybe someone can help. Have the Dometic 310 in my 2011 Outback. Have been experiencing no water coming into the bowl when you push the foot pedal unless I turn on the water tap in the bathroom. Thinking the valve was bad and due to excess pressure wouldn't open unless a tap was open, I replaced the valve. Worked well for first few flushes but back to same condition now. Pressure to city hook up is not excessive, could a faulty vacuum breaker cause this? When you press the foot pedal, the supply line shakes and makes a noise like air in plumbing lines as well until a tap is opened. Any suggestions?

[jvink]

I should add, there are no other plumbing issues at any of the taps or shower, only at the toilet.

[bobbecky]

Are you sure, when you installed the 310, you did not kink the water line going to the toilet water inlet? I know, on our rig, when I removed the Thetford and installed the 310, that the supply line connected to the opposite side of the toilet from the original connection position. Don't know why you would get flow with another faucet open, and not all the time.

[Lee]

Hum,.. out of curiosity,... does the flush operate when using the water pump as opposed to city water? Pump provides water at a lower pressure than city.

[jvink]

Thanks for the reply, when the water supply is disconnected, there is good flow coming from it.

[jvink]

I will definitely check with just running the pump. Maybe I can try closing the hose bib a bit, we are on a well with a pressure tank. 4 or 5 other trailers on same supply, haven't reported any issues. Its a strange one alright, considering there are only a few parts to these toilets.

[jvink]

So replaced the valve and the vacuum breaker and no change. I noticed the foot pedal now moves the valve body. Going to pull the cover off the toilet pedal and see what going on. Not sure how this relates to turning the tap on in order to flush but now no water enters the bowl. In the end, I suspect I will be that guy who should have just bought a new toilet. Hopefully this helps some others.

[Old Mustanger]

Originally Posted by jvink

So replaced the valve and the vacuum breaker and no change. I noticed the foot pedal now moves the valve body. Going to pull the cover off the toilet pedal and see what going on. Not sure how this relates to turning the tap on in order to flush but now no water enters the bowl. In the end, I suspect I will be that guy who should have just bought a new toilet. Hopefully this helps some others.

With the valve body moving with the foot pedal, the valve body is not seated correctly. This happened to me last winter when the DW tried to flush after traveling all day in subfreezing temps and broke the housing of the valve body. Evidently the valve had frozen and not thawed yet, put a pair of vice grips around the housing to keep the valve from moving out with the foot pedal, worked like a charm.

[jvink]

Well OM, you were right on. I discovered the pet line was too far out of the floor causing pressure on the valve and pushing it out of joint. Pushed it back into the floor and adjusted the water connection and the toilet functions as it should. Thanks for the replies.

[jvink]

“Pex” line.