Dometic toilet upgrade

Lars · 09-15-2020, 04:43 PM

Good evening. I have a leaking Dometic 300 toilet in my 2018 Springdale SS 2020QB. My question is: Do I have enough clearance from the wall to the flange to repalce it with a Domeic 310? Thank you for all you help.

**chuckster57** · 09-15-2020, 05:24 PM

I don’t see a reason it won’t fit. Check how high (profile) you need.

**sourdough** · 09-15-2020, 05:39 PM

I would think it would work but you might just pull up the install instructions to be sure. The rough in for the 300 is 8.5" and the 310 is 10". That may or may not make a difference depending on the design of one toilet vs the other.

rjrelander · 09-15-2020, 05:57 PM

Always surprised at the timing of other people's posts in this forum. We are looking at making the same upgrade for the same reason. I believe there was a "silent" recall (good will replacement) on Dometic 300 for leaking seals improperly installed at the factory where they sent out 310s as replacements so I'm assuming that they will fit. Ours is out of warranty and didn't show any signs until about a month ago.

rhagfo · 09-15-2020, 08:52 PM

Quote:

Originally Posted by Lars

Good evening. I have a leaking Dometic 300 toilet in my 2018 Springdale SS 2020QB. My question is: Do I have enough clearance from the wall to the flange to repalce it with a Domeic 310? Thank you for all you help.

Have you considered a 320 with elongated bowl?

NH_Bulldog · 09-16-2020, 03:50 AM

Quote:

Originally Posted by rjrelander

Always surprised at the timing of other people's posts in this forum. We are looking at making the same upgrade for the same reason. I believe there was a "silent" recall (good will replacement) on Dometic 300 for leaking seals improperly installed at the factory where they sent out 310s as replacements so I'm assuming that they will fit. Ours is out of warranty and didn't show any signs until about a month ago.

We are in the process of dealing with Dometic on our 300 toilet for the seal issue. Dealer has all the info and we are waiting for a response from Dometic at the moment. I called Dometic first since our trailer is 15 months old, and they wouldn’t deal directly with me, so we will see what the dealer can do. The difference between the 300 and the 310 is that the 300 is plastic and the 310 is porcelain. In the past, Dometic would replace the 300 with the same model or upgrade you to the 310 for $50. Size-wise I don’t think there is an appreciable difference.

wiredgeorge · 09-16-2020, 06:33 AM

Quote:

Originally Posted by rhagfo

Have you considered a 320 with elongated bowl?

Get the elongated bowl and the higher toilet.... 320 is vastly superior and is also porcelin lower part.

LewisB · 09-16-2020, 05:45 PM

Quote:

Originally Posted by sourdough

I would think it would work but you might just pull up the install instructions to be sure. The rough in for the 300 is 8.5" and the 310 is 10". That may or may not make a difference depending on the design of one toilet vs the other.

We've been looking at replacing a 310 with a 320 just due to the size. However, the roughout length for the 320 is 11". Anyone replacing a 300 with a 320 will need to be sure there is at least 2.5" of free space behind their current toilet in order to set the new toilet onto the gravity drain. If there isn't, then modification (moving) the floor drain system might be required. I'm not saying it can't be done - just make sure the dimensions of the replacement will fit the space available. Here's a link with some illustrations and associated dimensions:

Dometic_310_series_manual.pdf

I've never done this, but after our next trip I want to try. HTH

Summergirl · 09-16-2020, 07:17 PM

Quote:

Originally Posted by NH_Bulldog

We are in the process of dealing with Dometic on our 300 toilet for the seal issue. Dealer has all the info and we are waiting for a response from Dometic at the moment. I called Dometic first since our trailer is 15 months old, and they wouldn’t deal directly with me, so we will see what the dealer can do. The difference between the 300 and the 310 is that the 300 is plastic and the 310 is porcelain. In the past, Dometic would replace the 300 with the same model or upgrade you to the 310 for $50. Size-wise I don’t think there is an appreciable difference.

We are also in the process. Was told to contact the dealer. However, ours is getting the floor replaced as I type. 6 more weeks. Hopefully they will change out the toilet so there are no more issues with water. Now to work on the batwing antenna.

wiredgeorge · 09-17-2020, 03:16 AM

I change out the Thetford Aquamagic abomination first mod to my current trailer with a 320 as it is both taller and the seat shape accommodates human beings. The Aquamagic did not. Had sufficient room behind and installed a water cut off valve in the supply line (don't know why but it makes me feel good). Seems I used or had to use different bolts. Can't recall why. I also bought one of those little Dometic plastic valves that sometimes fail to ensure no camping trip was spoiled by not having it. I had one fail on a 310 I had in a Sunnybrook and it dribbled water. Never used it but if needed have it.

Javi · 09-17-2020, 04:33 AM

Quote:

Originally Posted by wiredgeorge

I change out the Thetford Aquamagic abomination first mod to my current trailer with a 320 as it is both taller and the seat shape accommodates human beings. The Aquamagic did not. Had sufficient room behind and installed a water cut off valve in the supply line (don't know why but it makes me feel good). Seems I used or had to use different bolts. Can't recall why. I also bought one of those little Dometic plastic valves that sometimes fail to ensure no camping trip was spoiled by not having it. I had one fail on a 310 I had in a Sunnybrook and it dribbled water. Never used it but if needed have it.

I did the same thing in my old Passport...

Lars · 09-24-2020, 04:18 PM

I would like to thank everyone who provided feedback to my post. You were a great help and, as a result, I went ahead and ordered the Dometic 310 to replace the 300 model. I just to let anybody out there with a Springdale 202QB that is thinking of doing the same: you will have enough clearance to do the upgrade, but it will be tight (see pics).

**sourdough** · 09-24-2020, 05:00 PM

Great job! I think you'll really like the 310.

Dallasrules · 10-01-2020, 04:26 PM

My 2003 Montana has a very short plastic Thetford. I am disabled, so I can't deal with the short height. Anyway, we are getting ready to put in a domestic 310.

rhagfo · 10-01-2020, 04:42 PM

Quote:

Originally Posted by Dallasrules

My 2003 Montana has a very short plastic Thetford. I am disabled, so I can't deal with the short height. Anyway, we are getting ready to put in a domestic 310.

If it will fit get a 320 with the larger bowl.

wiredgeorge · 10-02-2020, 04:40 AM

Quote:

Originally Posted by Dallasrules

My 2003 Montana has a very short plastic Thetford. I am disabled, so I can't deal with the short height. Anyway, we are getting ready to put in a domestic 310.

The Aquamagic ain't no fun. Not designed for the male anatomy. I replaced mine with a 320 tall version and it fits far better. Bowl is elongated and it is taller than the Thetford. I put in an inline water cut off valve when I did the install.

**sourdough** · 10-02-2020, 07:42 AM

You are making a wise choice getting rid of the Thetford; I've never had one I liked or without problems. Be sure and see what it is that the Thetford is leaking, there might be a stinky mess inside the plastic pedestal.

As far as the Dometic 310 it's a good toilet and the ceramic bowl is taller than a regular toilet so should be comfortable for you hopefully. With my bad knees I've had no problem.

310 vs 320. A few things are different. The 320 has an elongated bowl vs a round bowl on the 310. Some folks like the elongated bowl; especially men. For me it's not as comfortable as the 320 but DW hates the 320 more than I like it so we use the 310. The 310 has a "rimless" rinse where the water comes out of the side of the bowl just under the top edge in a circular motion. Works really well, but if you forget your water regulator in the location that has high water pressure, the lack of a rim will let that circular water motion without a rim just fly through the air into the room. The 320 has the top rim like a residential toilet and the water comes out from under it and can't do that. On either one I HIGHLY recommend getting the soft close wood lid/seat vs a regular wood, or heaven forbid, a plastic one.

Rough in for installation; the Dometic 310 is 10" from the back wall to center of the hole. 320 is 11". I don't know your wall clearance so you would need to double check. Any Thetford I've replaced with a 310 worked just fine. Here's a link to the clearances - click on page 7 -

https://www.manualslib.com/manual/16...?page=7#manual

spade117 · 10-02-2020, 09:43 AM

I've been considering this as my next upgrade. Thanks Sourdough for the detailed differences.

wiredgeorge · 10-02-2020, 10:55 AM

Only downside is that they don't let you test 310 vs 320 with your backside. bwhwhahahaha

**JRTJH** · 10-02-2020, 12:02 PM

Quote:

Originally Posted by wiredgeorge

Only downside is that they don't let you test 310 vs 320 with your backside. bwhwhahahaha

But, if you run across one of each during your shopping for a new trailer, close the door and "test the seat"... It could be an "eye opener" (no pun intended)...

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