Thetford vs Dometic Portable Toilet – Which Is Best?

Thetford and Dometic portable toilets in camper van

Disclosure: Some of the links in the article below may be affiliate links. This means that I may earn a small commission if you click on them and make a purchase.

If you are on the fence about which portable toilet to purchase for camping or use in your van or RV, I know exactly how you feel. I have owned both of these brands of portable toilets and have had plenty of time to compare two popular models from each to see which is the best.

Portable toilets are similar to cassette toilets, only portable. While a cassette toilet is fixed inside an RV, portable toilets give you the same benefits while also allowing you to carry it anywhere you want. These are great for camping or off-grid living.

Thetford and Dometic are both well-known in the industry and offer products of different types. Their portable toilet offerings are similar in the way they work but do have some key features that may set one above the other depending on your specific needs.

If you are looking to purchase a portable toilet, chances are, these two brands have come up during your search.

The two models of toilets I have owned are the Thetford Porta Potti 365 and the Dometic 976. Each of these is similar in size as far as capacity is concerned with only slight differences. However, there are other dimensional differences that may be important to you as well as functional differences. Let’s take a glance at these two side by side and see how they stack up.


Thetford Porta Potti 365Dometic 976
Fresh Water Tank4-gallons2.3-gallons
Waste Water Tank5.5-gallons5-gallons
Dry Weight11 lbs12 lbs
Footprint Size16.3″H x 15″W x 16.8″D13.5″H x 15.5″W x 16.5″D
Seat Opening8″ x 10-1/2″7-1/2″ x 8-3/4″
Warranty1 year1 year
Portable toilets in van with closed lids


Thetford makes some really nice portable toilets. They are among the most popular for those who rely on these for their vans, RVs, and other camping situations. They are small, comfortable, and well-made which are key considerations when it comes to this type of solution. Let’s look at some of the pros that I like about the Thetford Porta Potti 365.


Well Designed & Built

Thetford has thought of it all for the most part. The toilet has a great design to it and it gives you a lot of features for its size. In my experience, everything works as intended and the dumping experience is about as clean as it can get with a toilet like this.

The swivel dumping arm combined with the push button vent makes for easy work when it’s time for this often messy chore. There are some toilets on the market that don’t have a swing-out arm and just splash out of the dumping hole that is flush to the container making them hard to direct into a dumping site or toilet.

It’s these types of details that set some of these more expensive toilets apart.

Features get even better if you choose the larger Porta Potti 565. You’ll have the option for an electric flush, fresh water gauge, and toilet paper holder. All of this combined with a full-sized toilet seat.

Large Capacity

Fresh water: 4 gallons
Waste water: 5.5 gallons

For such a small footprint, this toilet has a large capacity for both fresh and waste water. This means that you can go longer between dumping the tank. I prefer to dump mine as often as possible but the large capacity gives you peace of mind in case you aren’t able to dump it for a few days. You won’t have to worry about it filling up so fast.

Seat Opening Size

Thetford seat opening dimensions

Many toilets in this size range feature a smaller opening in the seat and are very uncomfortable for adults. However, the Porta Potti 365 has a wider opening than most.

The seat opening measures approximately 8″ x 10-1/2″

This is much better than some of the other ones I have tried, including the Dometic discussed below. This makes it fairly comfortable to sit on for an adult.

The downside of this is that the seat itself is more narrow to allow for this larger opening. You won’t have the same surface area that you may be used to from the full-sized toilet in your home. However, you’d be hard-pressed to find a larger opening on a portable toilet in this size range.

Made Using Strong, Flexible Plastic

I have found this toilet to be very strong and flexible throughout my usage. I have used it time and time again on many trips and have never had an issue with anything breaking other than a faulty flush handle which I’ll mention below.

The plastic itself is a flexible type of plastic that bends easily and doesn’t feel as though it’s going to break, even in cold temperatures. I have dropped the toilet, moved it from vehicle to vehicle, dumped it many times and it has always been a workhorse for me that has stood the test of time.


Lip Seal Goes Bad & Begins To Leak

Bad lip seal on Thetford toilet

As mentioned above, the lip seal on my toilet went bad in less than a year. I tried to do all the things the manual said to take care of the toilet and didn’t even use it that much. However, the lip seal started leaking and eventually shriveled up and became totally useless. In the end, I’m not sure if it was my fault or if I got a faulty unit. This is a replaceable part in case this ever happens to you.

Customer Service

Products have issues and you may need to contact customer support or go through a warranty process. As mentioned previously, the lip seal went bad in it in less than a year’s time with minimal usage. I also had the flushing mechanism break on me as I was flushing it one day.

I was disappointed in this so reached out to customer service for warranty replacement. Initially they said they would replace the toilet for me and asked for my receipt. After sending them my receipt and some back and forth emails which took a few weeks, they said a replacement would be sent. They told me it would ship out the following week via UPS.

However, no replacement was ever sent to me. I emailed them back about it but got no response. I ended up giving up and purchasing a new one since it was needed.

UPDATE: Thetford finally sent me a replacement toilet and rather than replacing my Porta Potti 365, they upgraded me to the Porta Potti 565e. It’s much appreciated but I do wish they had gotten back with me to let me know one was on the way. You can read my review of the Porta Potti 565e here.


Much like the Thetford toilet from above, the Dometic 976 is a great option for those looking for a small toilet that has a good capacity. Many of the features are the same with slight differences.


Large Capacity

Fresh water: 2.3 gallons
Waste water: 5 gallons

While not as large as the Porta Potti 365, the Dometic toilet still offers nice sized holding tanks, especially for waste water. You will have to fill the fresh water tank more often but it will get most people through a few days of usage.

Carry Handles

Carry handle on Dometic portable toilet

The carry handles stick out on this unit making them obvious and easy to carry. They also provide a great way to loop a bungee cord through in order to store it away while driving. The Thetford is missing this feature and my bungee cord is usually just wrapped around the whole toilet itself.

These handles are sturdy and comfortable making the toilet easy to carry and dump.

Smaller Than The Thetford

This may be a pro but could also be a con if you are looking for a larger-sized toilet. I put it in the pros column because it is small and is easy to store away when not in use. If you only need one of these toilets occasionally, having one small in size is a great way to ensure it doesn’t take up much-needed room.

These are portable units so finding the smallest one that does the job is important. Of course, each person is different and will want something different. The size difference isn’t much but since the capacity on this one is smaller, the entire unit will take up a little less space.

Pressurized Push Button Flush

Dometic toilet push button flush

This toilet is marketed with less pumping in mind. The idea is that you pump the toilet up and then push a button when ready to flush. The button will allow you to flush multiple times before needing to pump it up with more pressure. It’s similar to a garden sprayer in which you pump it up and then the pressure allows you to discharge water into the bowl as needed.

I like this idea as long as it holds the pressure over time. I’m not sure about the longevity of this system. It could become a problem down the road as parts wear out or seals become less effective. This may render it useless if it stops holding pressure.

However, for now, it’s a great idea and convenient.


Small Seat Opening

Seat opening dimensions on Dometic portable toilet

The seat opening on this toilet measures in at approximately 7-1/2″ X 8-3/4″.

As you can see from the picture, it’s quite a bit smaller than the Porta Potti 365. This alone makes me shy away from it unless I need the smallest space-saving solution. For regular use, I like to have something a little larger that is more comfortable when using it.

This is perfect for children or small adults but can get quite uncomfortable for average to larger-sized adults.

Plastic Feels More Breakable

When using this toilet, I feel like it is going to crack under pressure. It’s a different feeling plastic than what the Thetford toilet is made of. It’s more of a rigid material that isn’t as flexible. It’s more fragile than the Porta Potti as I have seen from parts breaking under normal use.

Noisy Pumping

While the pressurized flushing feature is nice, the pumping required to pressurize it can be loud. This is especially noticeable in the middle of the night when you find it out of pressure and need to pump it while others are sleeping. Even pumping it slowly will produce a louder sound.

Customer Service

I had an issue with a broken toilet seat so contacted customer service for support. However, I never heard from them after multiple attempts.

Maybe I caught them during a bad time? I like to give them the benefit of the doubt. I have a Dometic refrigerator in my van as well and have had issues in the past and they were quick to respond and resolve the issue. Perhaps they just don’t take their portable toilets as seriously?

A Negative To Both of These Types of Toilets

Replacement parts

There isn’t much you can replace on these toilets other than the main seal and a few other small parts. Some portable toilets from other brands don’t even allow that. This means that once something goes wrong, you have to waste a large container of plastic. Tossing a big plastic box into the trash like this is hard to stomach if you are more environmentally conscious.

It would be nice if they made these with more replaceable parts so they wouldn’t create so much waste. It’s the nature of having the conveniences of products like this. In our throw-away society, when something goes wrong with a product we are using, it’s convenient to simply toss it in the trash and purchase a new one.


In my opinion, the Thetford Porta Potti 365 is the better toilet between the two.

I have used both and prefer the Thetford because of its larger seat opening and quality feel. Thetford also makes chemicals designed to work with their toilets so I like to stick with one brand in case something goes wrong.

Both of these have their place and if you prefer the smallest possible solution, the Dometic is probably the one for you. Neither are bad options but you’ll need to decide on the features that are important to you. Hopefully, the pros and cons outlined in this article along with my experience of using both will help you in your decision.

Dan Collins

I consider myself an outdoor enthusiast. I love to travel and go to places that most people don't get a chance to go. I want to see it all and live life to the fullest while I'm alive. My camper van is helping me to do just that. I write about my experiences to help inspire others to do the same.

Recent Content