Dometic 310/320 Questions

[sourdough]

I have removed the Thetford toilets from my last several trailers and replaced with a 310, this is the 3rd one. I've never had a leak (other than the water connection) from any of them until now. I have discovered what appears to be a leak originating between the upper bowl and pedestal. Researching it seems the seal between the upper and lower sections is problematic and the only way to repair it is to silicone the upper to the lower. I could but don't want to.

My first thought was to just go get a 320 with hopefully a better design. Everything I've found says the joint between the upper bowl and lower pedestal is sealed the same way in all the 300 series Dometics. If so I wouldn't gain anything by changing them out. DW likes the 310 but if the 320 is better she can adjust. If they're all the same I thought about going back to a Thetford (I cannot stand toilet leaks of dirty water). When I removed the one from this trailer (Thetford) it was obvious they had changed the "innards" but to what benefit I don't know. The other downside to that is I have all the spare parts for a Dometic which would be useless if I made a change back to Thetford.

Just reaching out for any experience dealing with this particular issue before I make a 2 1/2 hour round trip to bring back a 320 and it just starts leaking too.

[flyingjack]

2022 HC: changed to 320 almost immediately after new purchase; been nearly 19 months; used on five trips: approx 6K miles and 5 months. No issues and like the height and anatomically correct shape for men.
OBTW, I'm 240 lbs and not agile so toilet gets moved around.

[rhagfo]

Well we full Time and have had a 320 for five years, in that time replaced the ball seal once, and the flush valve once. I like that the bowl is designed like a residential toilet, with downward pointing rinse flow.
Can't think of a better toilet.

[sourdough]

Thanks guys. I'm wondering if anyone with a 320 has had a leak from the bowl/pedestal seal? I know lots of folks use the 320 and I've read on this forum of prior leaks on the 310. Trying to determine if it's a "family" problem with the 300 series (300/310/320 -I know the 300s had problems), 310 or all of them including the 320 - or if the 320 has been trouble free (seal).

Not as urgent as it was yesterday after finding today I need to replace my main A/C to the tune of 28xx. I do however want to take care of it fairly soon. TIA

[Mikendebbie]

Danny - just sent you a PM.

[sourdough]

Originally Posted by Mikendebbie

Danny - just sent you a PM.

Thanks Mike. Got it and responded.

[sourdough]

To close this matter;

I couldn't find much about the construction of the bowl to pedestal mount about the 320 and not much detail on the 310 other than it was 2 piece with a gasket and screws to hold them together which I don't like.

Talked to Dometic today to discuss the differences and a couple of things were of interest; the 320 has a porcelain bowl and the 310 is ceramic. I don't know that it makes a lot of difference but IMO the porcelain would be better. The 320 is not screwed together between the bowl and ped like the 310, they are made together - plus for 320. Of course we know that the 310 is jetted from the sides of the bowl and the 320 jets from under the rim. The fellow said that the 320 is basically more residential than the 310 (and here I've been buying 310s). CW in Tallahassee is holding a 320 for me to pick up tomorrow and had to tell DW that those 310s won't be coming into our RVs anymore....

[wiredgeorge]

320s come in a few configurations. They have a tall which I very much prefer. Ours is oval and I don't recall if that is a configuration option or they are all like that.

[sourdough]

320s are all oval and come in either the tall (18") or standard which is 15" or less IIRC.

[bobbecky]

Originally Posted by sourdough

To close this matter;

I couldn't find much about the construction of the bowl to pedestal mount about the 320 and not much detail on the 310 other than it was 2 piece with a gasket and screws to hold them together which I don't like.

Talked to Dometic today to discuss the differences and a couple of things were of interest; the 320 has a porcelain bowl and the 310 is ceramic. I don't know that it makes a lot of difference but IMO the porcelain would be better. The 320 is not screwed together between the bowl and ped like the 310, they are made together - plus for 320. Of course we know that the 310 is jetted from the sides of the bowl and the 320 jets from under the rim. The fellow said that the 320 is basically more residential than the 310 (and here I've been buying 310s). CW in Tallahassee is holding a 320 for me to pick up tomorrow and had to tell DW that those 310s won't be coming into our RVs anymore....

Not sure what position the individual was in at Dometic, but they don't seem to know their product. The 320 as well as the 310 have ceramic bowls attached to the plastic bases. This is a link for the Dometic page for the 320, and the photo shows the joint between the ceramic bowl and the plastic base, and the description below the photo specifically states the bowl is ceramic. https://www.dometic.com/en-us/outdoo...etic-320-25297

[sourdough]

Originally Posted by bobbecky

Not sure what position the individual was in at Dometic, but they don't seem to know their product. The 320 as well as the 310 have ceramic bowls attached to the plastic bases. This is a link for the Dometic page for the 320, and the photo shows the joint between the ceramic bowl and the plastic base, and the description below the photo specifically states the bowl is ceramic. https://www.dometic.com/en-us/outdoo...etic-320-25297

Yes, I had seen those descriptions and asked the individual (300 series toilet specialist?) twice about that difference when he told me; he confirmed twice that it was porcelain vs ceramic. I have tried calling them back this AM but will have to wait until they open.

Dometic does not show the bowl to pedestal as being serviceable with no parts breakdown. From the Dometic manual;

5 Maintenance
Properly cleaning, winterizing, and maintaining
your toilet will increase its lifespan.
NOTICE: If this toilet ever requires service,
read the following statements before servicing
the product. Failure to follow these guidelines
can cause product damage and can void your
warranty coverage:
• Do not separate the ceramic bowl from the
plastic base. Unlike other Dometic footpedal toilets, the bowl and base of the 300,
310, and 320 series toilets should not be
separated for any reason.
• Do not remove the foot pedal from the base.

However I have found a parts breakdown that does show the gasket/bands for use between the two. I am going to verify again today that the 320 is built differently than the 310 in that respect...which he said twice yesterday was different. I have no desire to pull a toilet yearly to tighten 4 screws "up yonder" inside the interior dump channel to make sure nothing is coming loose, that was a requisite for the Thetford IIRC. I can't find anything that says the 320 is built differently between the bowl and ped but ??

[sourdough]

One last update;

Called Dometic again this AM. The lady this morning confirmed what I always thought as well as most of us I suspect; the guy yesterday didn't know what he was talking about. The 310 and 320 are built the same with the same materials for the bowl (ceramic). They both have the non replaceable gasket in between with the 4 screws. That is what I've always thought and what any diagrams I ever found seemed to indicate - she confirmed. She would not address the conflicting information the other guy gave me but I gave her his name in the hopes he receives some education. The lady said the 310/320s seldom leak but sometimes they do.

Be that as it may since I asked them to hold the 320, and I really don't want to dig into the existing toilet, I'm headed off to pick up the 320 and slap it in. I've never had a 310 leak before and I'm hoping the 320 is the same.

[SteMax]

After a less than exhaustive search but relatively thorough, it would seem to me the the only substantive difference between the 310 and the 320 is the elongated bowl on the 320 versus round bowl on the 310.

[sourdough]

Originally Posted by SteMax

After a less than exhaustive search but relatively thorough, it would seem to me the the only substantive difference between the 310 and the 320 is the elongated bowl on the 320 versus round bowl on the 310.

Yes, that's what I thought all along until the technical assistance person (first one) at Dometic told me otherwise which put me into a "what the heck" mode. Second tech person corrected the information.

The 320 is in now....we both like the 310 better so far. Had to make a hurried trip to the city to get a soft close wood toilet seat which we prefer. The 310 came with one but the 320 didn't. I assumed it would so did not check the box. If I had I could have stopped and got one while in the city vs making another 3 hr. round trip just for a toilet seat. I will note that the 310, although rimless, has a better bowl cleaning action than the 320 - a lot better.

[CedarCreekWoody]

Danny FYI: my 310 did not come with a soft close lid.

[sourdough]

Originally Posted by CedarCreekWoody

Danny FYI: my 310 did not come with a soft close lid.

I'm thinking maybe it was a special run or something? Bought it about June 2020 I think at CW. Had a little info box on the toilet box specifying the soft close lid. I was surprised but happy about it. It may be that it's not just a normal thing.

[hlh1]

I bought and installed my 310 last month and it has a soft close...

[JRTJH]

The Dometic line of toilets several years ago included the 310 with plastic seat, 320 with painted wood seat... Sometime during the "lockdown" Dometic started shipping the 310 models with a soft close seat and the price increased from around $175 to $299. All of the 2023 Keystone trailers that I've seen on lots have the plastic seat, so apparently there's a "contractual agreement" between Keystone and Dometic to supply the "cheaper, old style seat for OEM"... But, all the toilets that I've seen in the parts department at CW and the local parts stores around this area, come with the soft close seat.

There is a soft close seat kit available from Dometic for around $75 to replace the plastic seat with the Dometic soft close seat.

The 320. as far as I can remember, has always been sold with the "standard close wooden seat". The MSRP is $499, up from $279 just 2 years ago. So, looks like the price of wood has taken a dramatic rise recently

All that said, I'd imagine there are some mom and pop RV parts stores that still have some "pre-COVID" toilets sitting on the shelf, gathering dust, so inventory in any location may well have 310's with plastic seats, "slam close seats" or current slow close seats.....

I'd "hazard to guess" that with the "post-COVID" supply chain problems, there's likely no rhyme nor reason to anything any more and just like the automobile industry's "refund of standard equipment" on the window sticker as they build cars without adequate inventory to install all they designed into the vehicle, toilets are apparently subject to the same "lack of supply parts"...

[spade117]

Originally Posted by JRTJH

The Dometic line of toilets several years ago included the 310 with plastic seat, 320 with painted wood seat... Sometime during the "lockdown" Dometic started shipping the 310 models with a soft close seat and the price increased from around $175 to $299.

I replaced the 300 with a 310 back in June 2021 and it came with a slow closing lid. I do not remember the cost, but I do not think it was more than $200 at the time.

[rhagfo]

I just looked at 320’s and CW has them at $261.58 for the tall one.