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2oldman's avatar
2oldman
Explorer II
Sep 08, 2014

Dometic 310 toilet

I just finished installing this new Dometic '310' toilet:



I tried installing the 320 model which is bigger, nicer and heavier, but I didn't have enough clearance to the back wall. There's a "rough in" dimension page which I missed in my research, which would have told me it wouldn't fit. However, according to that guide, this 310 model shouldn't fit either, but it does.

As you can see, I've used a flexible household water hose. Finger tight, no leaks. After a few flushes, I noticed the water was continuing to trickle in the bowl, but that only lasts a few seconds after the foot valve is shut. I hope it stays that way.. I sure don't want to have to return another one!

The seat is pretty cheesy. It's thin and light, and I may replace that with a household seat.

My biggest problem was replacing the 2 upright mounting bolts that slide into the floor flange. I got them out ok (well, they didn't just pull right out), but getting the new ones in was not happening. I could only slip them in the "long" way, which means the oval-shaped head was parallel to the floor flange opening, not perpendicular as I'm sure it should be. I hope when I tightened the nuts that these heads turned a bit to get a better grip.
  • Ron3rd's avatar
    Ron3rd
    Explorer III
    jodeb720 wrote:
    Our 310 does exactly the same thing.

    Our seal does work - most of the time, but as I've been instructed in the manual and here:

    Turn off external water pressure (pump off or pipe valve off)
    Open sink/hot water and let out pressure.
    Fill toilet with hot water
    let water sit for about a minute
    Open valve all the way
    press down on the black seal pushing it down towards the bottom of the toilet.
    Note: Don't ask me how I know it, but sometimes the seal will come away (it's a snap in single piece seal) and with the valve open, you need to snap it back in place, and get it back into it's original position (yes, it's a pain, but with gloves on, you get the feel for it).
    Close the valve and pour more hot water in the bowl until the water is room temperature (maybe 10-15 minutes)

    Works like a champ every time for a few weeks, and then it'll start to slowly leak again.

    I like the toilet, hate the seat the seal is functionally painful...


    I followed the same advice and it worked great. I believe you posted this info earlier and it caught my eye as my seal would not hold water for some reason. I was going to order a new seal but saw your post and gave it a try.
  • Ron3rd's avatar
    Ron3rd
    Explorer III
    Dog Folks wrote:
    2oldman wrote:
    I just finished installing this new Dometic '310' toilet:
    ........After a few flushes, I noticed the water was continuing to trickle in the bowl, but that only lasts a few seconds after the foot valve is shut. I hope it stays that way.. I sure don't want to have to return another one!


    For what it worth , our 310, (installed 12/13) does the same thing. I believe it is that way on purpose to insure a little water in the bowl. Possibly to keep the seal wet. That is my best guess.


    I think it's designed to do that, at least our 310 always has. I think it's their method of filling up the bowl a bit after flushing.
  • Thanks. I'm hoping to get many years of leak-free operation. It is tricky just putting water in the bowl. Very sensitive lever.

    Amazon is so good about returns. The moment the UPS return label was scanned, they began processing my refund on the returned 320. I wish every company was this efficient.
  • Our 310 does exactly the same thing.

    Our seal does work - most of the time, but as I've been instructed in the manual and here:

    Turn off external water pressure (pump off or pipe valve off)
    Open sink/hot water and let out pressure.
    Fill toilet with hot water
    let water sit for about a minute
    Open valve all the way
    press down on the black seal pushing it down towards the bottom of the toilet.
    Note: Don't ask me how I know it, but sometimes the seal will come away (it's a snap in single piece seal) and with the valve open, you need to snap it back in place, and get it back into it's original position (yes, it's a pain, but with gloves on, you get the feel for it).
    Close the valve and pour more hot water in the bowl until the water is room temperature (maybe 10-15 minutes)

    Works like a champ every time for a few weeks, and then it'll start to slowly leak again.

    I like the toilet, hate the seat the seal is functionally painful...
  • 2oldman wrote:
    Dog Folks wrote:
    I believe it is that way on purpose to insure a little water in the bowl. Possibly to keep the seal wet. That is my best guess.
    Great, thanks! Wish they said these things in the manual.

    It's just nice to have a toilet that doesn't leak out of the bowl. Been putting up with that for probably 2 years.


    On the back of toilet just behind seat is a vacuum breaker (small container with a hole and flapper). Under water pressure vacuum breaker fills (flapper seals hole off) as water flows into bowl around/thru rim holes. Then when water valve closes flapper drops open air enters vacuum breaker and the water drains out into bowl. This allows water to cover bowl seal (vapor barrier) and relieves pressure downstream of water valve.
  • Dog Folks wrote:
    I believe it is that way on purpose to insure a little water in the bowl. Possibly to keep the seal wet. That is my best guess.
    Great, thanks! Wish they said these things in the manual.

    It's just nice to have a toilet that doesn't leak out of the bowl. Been putting up with that for probably 2 years.
  • 2oldman wrote:
    I just finished installing this new Dometic '310' toilet:
    ........After a few flushes, I noticed the water was continuing to trickle in the bowl, but that only lasts a few seconds after the foot valve is shut. I hope it stays that way.. I sure don't want to have to return another one!


    For what it worth , our 310, (installed 12/13) does the same thing. I believe it is that way on purpose to insure a little water in the bowl. Possibly to keep the seal wet. That is my best guess.

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