Dometic model 300 odor problem and replacement

[Ree]

Originally Posted by tperk100

Even after lots of chemical in tanks, our bath smells like the tank is opened up to the room. Seems strongest odor is near toilet. Seal is good. It holds water for days. There is no obvious leaking or loose connections. No mold, mildew, stains anywhere including under sink.

I think problem is with toilet but have no idea of what it might be. Any thoughts?

Thanks

This what we found!
HOLDING TANK ODOR IN TRAILER
(with ample black water chemicals)

Camping in Florida's 90 degree weather brings out odors. We noticed a strong odor in the bathroom after three days on our V-Lite with a front bathroom. Following my nose it was a weak odor in the bedroom and stronger in the bathroom. Opening the sink cabinet almost knocked me out. The odor was strongest on the left side where the sink drain runs through the wall in a hole 50% larger than the pipe.

Turning on the bathroom fan seemed to clear the odor in the bathroom but it got stronger in the bedroom. I suspected the sewer holding tank vent was cracked or the seal was defective. From the outside, I noticed the vent pipe runs up the bedroom wall and through the roof, RIGHT IN FRONT OF THE VENT FAN!

Back home, I took the bedroom wall down and found the hole through the roof and floor 50% larger than the pipe and no sealer. We drained the holding tanks before leaving the campground. At home, we over-filled the tank to make sure the vent pipe seal on the tank was OK. It was fine. Moving to the roof, I dug out the caulking on the vent pipe cap screw. Removing the screw and pulling the cap off exposed the source of the odor. The vent pipe was cut short and was below the roof cap top ring where it is supposed to seal around the pipe. So the STINK goes up the pipe and fills the roof cap and then down into the bedroom/bathroom wall and follows the drain pipe to the bathroom cabinet.

Whoever installed the roof cap knew the pipe was short and would not seal against the pipe. The cap was not even centered on the vent pipe. I checked the other two vent caps. The kitchen galley tank vent cap was OK but the shower waste water cap was the same as the sewer cap, short cut and off center. And why would anybody place a sewer vent right in front of a vent fan?

SOLUTIONS: The vent/drain holes through the roof, floor and walls were all sealed with spray foam. The gap around the roof cap and the vent pipe was filled with foam to overflowing and the vent hole inside the pipe was cut out with a knife. The cap was replaced and the screw caulked up.

For most owners with this problem, fixing the roof vent cap seal around the vent pipe will take care of it.

For Florida hot weather now using only
Thetford Aqua-Kem

[digger47]

The problem with this toilet is the seal inside the base. We went through the same issue and as soon as we lifted the base, we found the problem. We upgraded the toilet and have not had an issued since.

[Versus3]

Is this still an ongoing problem? We have a 2018 FR3 and have the same odor problem.

[tperk100]

Originally Posted by Versus3

Is this still an ongoing problem? We have a 2018 FR3 and have the same odor problem.

If the odor is the strongest from the rear of the toilet, and if you have a 300 you should get its serial number and call Dometic to ask.

[Versus3]

Called Heidi at Dometic; told her serial number, and within 5 minutes she had a replacement toilet on its way to us! We chose to upgrade to 320 model; cost us $100. Terrific customer service!!

[rk06382]

Originally Posted by Versus3

Called Heidi at Dometic; told her serial number, and within 5 minutes she had a replacement toilet on its way to us! We chose to upgrade to 320 model; cost us $100. Terrific customer service!!

You will love your 320.

[Paul GA]

You will however hate the flush valve.

[5picker]

Originally Posted by Paul GA

You will however hate the flush valve.

Care to expound?

[Paul GA]

Originally Posted by 5picker

Care to expound?

They tend to develop a leak at least once a year. And not just in the winter months! My last replacement is different they added little plastic gussets to the water in connection. Perhaps that will help.

[Astles]

Had that weird nasty urine-like smell in 2017 Rockwood 2902WS bathroom. CS tech asked if the smell was coming from the rear of the 300 series toilet, which it was. Upgraded to the 310 with the ceramic bowl for $50 more, solved the problem and it no longer sounds like I’m wrestling a gorilla like the 300 experience. Very satisfied and all problems are solved.

[Paul GA]

Originally Posted by Astles

Had that weird nasty urine-like smell in 2017 Rockwood 2902WS bathroom. CS tech asked if the smell was coming from the rear of the 300 series toilet, which it was. Upgraded to the 310 with the ceramic bowl for $50 more, solved the problem and it no longer sounds like I’m wrestling a gorilla like the 300 experience. Very satisfied and all problems are solved.

I’m curious what you were doing that caused a sound like you were wrestling a gorilla...

[intotec]

I can’t believe 5 years later after a problem was found domedic still has not fixed it. I have a 2019 Rockwood and it has a 300 that smells like piss. This is crazy that FR and Domedic still use and sell the crap.

[Paul GA]

Originally Posted by intotec

I can’t believe 5 years later after a problem was found domedic still has not fixed it. I have a 2019 Rockwood and it has a 300 that smells like piss. This is crazy that FR and Domedic still use and sell the crap.

After Dometic told me 50 degrees is acceptable in my new fridge, nothing about Dometic surprises me anymore.

[rk06382]

Originally Posted by intotec

I can’t believe 5 years later after a problem was found domedic still has not fixed it. I have a 2019 Rockwood and it has a 300 that smells like piss. This is crazy that FR and Domedic still use and sell the crap.

It is a weight issue. 300 is 8 lbs vs 310 (22.75 lbs) or 320 (37 lbs). Also a lot of people forget to refill the bowl.

From Dometic 300-320 installation_manual_55249:
Dometic 300-320 installation_manual_55249.pdf
Note:

To ensure holding tank odors do not enter the living space, make sure 1 inch (24 mm) of water remains in the toilet bowl. Depending on variations in plumbing systems and user operation, the “add water” function may be required to achieve the 1-inch water depth.

(I can no longer find this PDF on the Dometic website.)

[intotec]

When I contacted dometic they said there is a gasket that was pinched on some of the 300's but they have fixed the problem. They are sending me a 320 upgrade for 100.00.

[Biolerdad]

We seem to having the same issue with 2018 Heritage Glen we purchased in February. Has anyone had luck with dealer just replacing toilet? We are on the road and need our toilet!

[Astles]

Originally Posted by Biolerdad

We seem to having the same issue with 2018 Heritage Glen we purchased in February. Has anyone had luck with dealer just replacing toilet? We are on the road and need our toilet!

I had mine shipped directly from Dometic. However, I imagine you could contact Dometic customer service prior to going to a dealership and they could work it out with the dealer. Or they could assist with a reimbursement. Either way, definitely contact cs first, and they’ll assist from there.
They were extremely helpful and knew exactly what the problem was. And I upgraded to a full porcelain bowl at that time for $50...well worth the money. Have a pic of the serial number and model for them. Good luck

[Biolerdad]

Did you install? How difficult was it?

[ependydad]

Originally Posted by Astles

I had mine shipped directly from Dometic. However, I imagine you could contact Dometic customer service prior to going to a dealership and they could work it out with the dealer. Or they could assist with a reimbursement. Either way, definitely contact cs first, and they’ll assist from there.
They were extremely helpful and knew exactly what the problem was. And I upgraded to a full porcelain bowl at that time for $50...well worth the money. Have a pic of the serial number and model for them. Good luck

It's been a few years, but when I needed my Dometic toilet replaced, they helped me pick a service center nearby and shipped the toilet directly to them. Dometic also paid the service center for installation.

I'm sure they'd do the same with a dealer, but I try to avoid dealerships for service issues.

[nomad297]

This thread has been here for so long and I have never read it from the beginning to here.

It is obvious to me that the Dometic 300 toilet is a bad product that allows smells to get into the camper, but I haven’t come across the post in this thread that explains what, exactly, the problem is. What is it about this toilet that causes the problem everybody has with it?

Bruce