Dometic 310 vs 320: Which RV Toilet Suits You Best?

When choosing between the Dometic 310 and 320, consider your space and comfort needs: the 310 fits tight RV spots with a compact, round bowl and 10-inch rough-in.

The 320 offers an elongated bowl, better ergonomics, and requires 11 inches of floor space. Both use reliable foot pedal flushing, but the 320 is more water-efficient and durable with higher-quality materials.

Installation differences affect compatibility, so understanding these details helps optimize your setup. Explore further to find which fits your RV or outdoor bathroom best.

Key Takeaways

• The Dometic 310 is compact with a 10-inch rough-in, ideal for small RVs, while the 320 requires an 11-inch rough-in for larger spaces.
• Model 320 features a full elongated porcelain bowl offering greater comfort and better odor control compared to the 310’s partial bowl.
• The 320 uses a more efficient, quieter gravity flush system with about one pint of water per flush versus the 310’s pressure-enhanced flush.
• Both have durable vitreous china bowls, but the 320 includes metal lever pedals for longer-lasting flushing mechanisms over the plastic parts in the 310.
• Installation differences include the 320 needing more rear clearance and eight flange screws; the 310 is lighter and easier to install in tight quarters.

Side-by-Side Look: Dometic 310 and 320 Features

Feature	Dometic 310	Dometic 320
Bowl Shape	Round, compact – ideal for tight RV spaces	Elongated – enhances comfort and ergonomics
Rough-In	10-inch – fits smaller bathrooms	11-inch – requires slightly more space
Flush System	Pressure-enhanced gravity flush	Efficient gravity flush – uses ~1 pint per flush
Pedal Mechanism	Plastic lever pedals	Metal lever pedals – longer-lasting and durable
Weight	~41 lbs – easier to handle in tight spaces	~37 lbs – lighter design, slightly easier setup
Front-to-Back Dimension	19 inches	22 inches – extra legroom
Seat Height	18 inches	18 inches – residential-style seating
Material Quality	Vitreous china bowl	Premium vitreous china bowl – improved durability
Maintenance	Easy valve access, regular cleaning needed	Simplified seal replacement & enhanced water efficiency
Installation	Lightweight, fewer screws needed	Requires more rear clearance and 8 screws

Bowl Shape and Seating Comfort Comparison

When comparing the bowl shapes of the Dometic 310 and 320, you’ll notice the 310 uses a compact, round design that saves space and simplifies cleaning.

The 320 adopts an elongated, deeper bowl resembling residential toilets to enhance seating comfort and provides better ergonomic support for extended use.

The 310’s round bowl is ideal if your RV bathroom is tight or you want minimal surface area for easier maintenance.

The 310’s round bowl suits tight RV bathrooms and offers easier cleaning with less surface area.

In contrast, the 320’s elongated bowl provides a larger seating surface, improving ergonomics and comfort, especially for adults.

Both models maintain a residential seat height near 18 inches, but the 320’s deeper bowl also helps reduce splashing.

Remember, the shape difference affects installation compatibility and bathroom layout. Measure your space and rough-in distance carefully before deciding between these models, as rough-in measurement is essential for proper fit and function.

Flushing Mechanisms and Durability Features

Although both the Dometic 310 and 320 employ foot pedal flushing to promote hygiene by minimizing hand contact, their flushing mechanisms differ notably. The 310 uses a pressure-enhanced gravity flush system that generates a powerful swirling action for efficient waste removal.

Both models share similar flush ball, rotor shaft, and cartridge components whose material composition impacts durability and maintenance requirements. You’ll find the 320 built with premium materials offering enhanced robustness compared to the 310’s vitreous ceramic bowl and plastic base.

Both models use metal levers in their pedal assemblies, improving longevity and ease of maintenance. The 310 model weighs approximately 28 lbs 11 oz, making it about half the weight of traditional home toilets, which simplifies installation and handling lightweight design.

• 310’s flush system creates strong swirl for effective waste clearance
• 320’s premium build boosts durability beyond 310’s mid-tier level
• Shared flush components vary in material quality, affecting lifespan
• Metal pedal levers enhance durability and reduce wear over plastic-only designs

Installation Requirements and Space Considerations

Since space constraints often challenge RV bathroom upgrades, understanding the installation requirements of the Dometic 310 and 320 is essential.

The 310 requires a 10-inch rough-in from flange center to wall, while the 320 needs 11 inches due to its deeper 22-inch front-to-back dimension versus 19 inches for the 310.

Both share a 15-inch width and 18-inch seat height, mounting on a 3-inch flange with 6-11 mm thickness. It is important to turn off water supply before removing or replacing the toilet to avoid any water damage during installation. Using durable materials for mounting ensures long-term stability and prevents leaks.

Confirm a flat, stable surface and secure the flange with at least four screws; eight screws are preferred for the 320 to prevent leaks and movement.

Water supply fittings are identical; plumbing swaps are straightforward if rough-in dimensions match.

Note the 320 demands more clearance behind the flange and floor space, impacting retrofit feasibility in tighter RV bathrooms.

Material Quality and Longevity Factors

Understanding the material quality and longevity of the Dometic 310 and 320 is essential for making an informed choice that suits your RV lifestyle.

Both models use vitreous china bowls, offering superior durability, stain resistance, and a residential feel compared to plastic alternatives. This material choice parallels the importance of selecting durable tire materials for enhanced longevity in trailers.

Vitreous china bowls provide enhanced durability, stain resistance, and a premium, residential-quality feel over plastic options.

Their flush mechanisms feature foot pedal actuation, designed for durability and hygienic use, with easy seal replacement from the top.

Structurally, porcelain provides robust support, handling heavier users without issues, while maintenance remains straightforward.

Vitreous china bowls resist discoloration and damage over time.

Durable foot pedal flush mechanisms reduce failure risk.

The Dometic 320 offers a gravity flush system that uses approximately one pint of water per flush, enhancing efficiency and performance.

Easy top-access seal replacement simplifies upkeep.

Both models share consistent structural strength and longevity.

This ensures you invest in a reliable, long-lasting RV toilet tailored to your needs.

Compatibility With RV Plumbing Systems

Choosing between the Dometic 310 and 320 goes beyond comfort and flushing performance. You also need to make certain of compatibility with your RV’s plumbing system.

The primary consideration is the rough-in dimension: 310 fits within 10 inches, while 320 requires 11 inches. Both share identical mounting flange and bolt hole locations, easing direct replacement if space allows. It is important to measure the distance from bolts to the back wall carefully, as the Dometic 320’s rough end is slightly larger than the available space in some RVs, making it less suitable. Fitment considerations Additionally, ensuring proper installation and maintenance can prolong the life of the system and prevent leaks.

Their water supply connections use the standard 0.5 inch NPT fitting, matching typical RV plumbing without rerouting.

The 3-inch discharge flange is also compatible for both, ensuring straightforward installation.

Key compatibility factors include:

• Rough-in space: 10″ for 310, 11″ for 320
• Standard 0.5″ NPT water inlet, same height and position
• 3″ floor flange with consistent discharge outlet
• Pressure tolerance: 30-100 PSI, with freeze vulnerability considerations

Confirming these ensures a seamless swap or upgrade.

Maintenance Tips for Optimal Performance

Hey there! If you own a Dometic 310 or 320 toilet, here’s a little tip: make sure to clean those valves regularly. This helps prevent any pesky mineral buildup that can mess with how well everything works.

Just grab a damp microfiber cloth—no need for harsh chemicals, as they can harm the seals. Keeping it simple helps ensure everything operates smoothly and maintains proper device compatibility within your RV systems.

Plus, by staying on top of valve maintenance, you’re not just fixing a short-term issue; you’re actually extending the lifespan and reliability of your entire RV plumbing system. So, it’s a win-win!

Remember, service and maintenance must be performed exclusively by qualified personnel to ensure safety and proper operation.

Valve Cleaning Procedures

Although valve cleaning might seem straightforward, following precise procedures guarantees your Dometic 310 or 320 toilet maintains ideal performance and longevity.

Start by turning off the water supply to avoid leaks. Use a soft bristle brush and a putty knife to clean the flush ball and seal carefully, applying a non-abrasive cleaner like Dometic toilet bowl cleaner. Regular maintenance is essential because it helps prevent calcium buildup that can damage the valve seal and cause odors. Using maintenance-free batteries in other RV systems can similarly reduce upkeep time for overall RV reliability.

Avoid wearing gloves that reduce grip but clean your hands afterward. After cleaning, inspect the valve surface to assure it’s smooth and free of debris for proper sealing.

Depress the flush pedal, then remove the seal carefully for thorough cleaning. Apply light downward brushing to dislodge dirt without damaging components.

Use silicone lubricant on seals during reassembly to enhance durability. Test the valve post-cleaning to confirm ideal operation and leak prevention.

Preventing Mineral Buildup

Since mineral buildup can severely impair your Dometic 310 or 320 toilet’s performance, regular cleaning is essential to maintain ideal function and prevent leaks.

Use Dometic Toilet Bowl Cleaner or a non-abrasive cleaner to clean the bowl, focusing on the flush ball and seal where deposits cause leaks.

Gently press and release the flush pedal to loosen debris, then use a soft brush to remove stubborn mineral buildup under seals.

Manage hard water by installing compatible water softeners and flushing with clean water regularly.

Inspect and clean the water valve screen and rim holes to prevent clogging.

Before storage, drain water and apply RV antifreeze to protect seals.

Promptly replace damaged seals using Dometic parts for durability and apply silicone lubricant during reassembly.

Comparison With Similar Models on the Market

When you take a look at the Dometic 310 and 320, and compare them to models like Thetford’s Aqua-Magic series, you’ll notice that they fall pretty much in the same ballpark when it comes to price and core features.

For instance, the 320 has an elongated bowl that really ups the comfort level, similar to what you’d find in many competitor models. On the other hand, if you’re tight on space, the compact design of the 310 might be just what you need.

Now, let’s talk installation. The 310 requires a 10-inch rough-in, which is a bit different from the 11-inch rough-in that the 320 and most Thetford models use.

This can definitely impact how well they fit in your RV, depending on the layout and space you’re working with. So, keeping those measurements in mind is key when you’re making your decision!

Additionally, if you’re planning to use your RV in colder climates, considering accessories like heated water hoses can help prevent freezing and maintain water flow.

Design and Comfort

Although both the Dometic 310 and 320 share similar compact designs tailored for RV bathrooms, the 320’s slightly larger rough-in dimension of 11 inches demands more clearance and affects installation options.

You’ll notice the 320 offers a marginally larger footprint and an extra inch of legroom, enhancing comfort for users seeking more space without sacrificing ergonomics.

Both models feature smooth, easy-to-clean surfaces and sturdy seats with quality hinges, ensuring durability in mobile environments. Additionally, the use of robust construction in these models helps withstand the rigors of travel and frequent use.

Compared to similar RV toilets, the 310 is better suited for very tight spaces, while the 320 balances comfort and size effectively.

You’ll also appreciate the 320’s minor improvements in water flow control, offering quieter and more efficient flushing, which slightly edges it ahead in user comfort.

Installation and Compatibility

The slight differences in size and design between the Dometic 310 and 320 directly influence their installation requirements and compatibility with existing RV plumbing systems.

Both need precise floor flange positioning: 10 inches for the 310 and 11 inches for the 320 from the back wall. This affects how they fit into your RV’s layout.

While sharing gravity-flush operation, these toilets differ from power-flush or cassette models. They demand specific flange dimensions and mounting angles.

Key considerations include:

• Secure fastening with multiple screws and proper floor flange seals to prevent leaks.
• Snug fit against surrounding walls for stability during travel.
• Compatibility with existing water supply lines, focusing on sealing integrity.
• Limited ventilation needs compared to refrigeration units, but space planning remains critical for adjacent appliance access.
• For example, refrigeration units like the Dedick NR NRX 130C model require adequate ventilation via ventilated back and side walls to ensure optimal airflow.

Choosing between them depends on your RV’s plumbing layout and installation space.

Suitability for Different RV and Outdoor Settings

Choosing between the Dometic 310 and 320 involves more than just price and features; you’ll want to contemplate how each model fits your specific RV or outdoor setup.

The 310’s compact design suits smaller RVs and campers where space is at a premium. It offers a durable partial porcelain bowl ideal for mobile use. Additionally, the 310 model is known to be heavier by 30 lbs, which may impact towing considerations for lightweight campers.

Conversely, the 320’s full porcelain elongated bowl enhances comfort and is better for larger RVs or fixed outdoor bathrooms.

Consider your installation space, water resources, and desired user comfort when choosing.

Dometic 310 fits tight spaces, ideal for lightweight campers.

Dometic 320 requires more room, perfect for semi-permanent cabins.

Both operate mechanically, no electricity needed, supporting off-grid use.

320’s superior seal system reduces odors, enhancing outdoor comfort.

Frequently Asked Questions

Are Replacement Parts for Dometic 310 and 320 Interchangeable?

Yes, replacement parts for the Dometic 310 and 320 are interchangeable. You can use foot pedal repair kits, seal and gasket kits, and mounting hardware across both models without modification.

Many aftermarket kits are designed to fit these toilets, simplifying repairs. When installing, you’ll need basic tools, and parts like pedal assemblies and floor flange seals fit both models seamlessly.

This allows you to maintain or repair your toilet efficiently without buying model-specific components.

Do Dometic 310 and 320 Toilets Come With Seat and Lid Included?

Yes, your Dometic 310 and 320 toilets come with a seat and lid included.

Both models feature full-size seats: polypropylene for the 310 and options like wooden upgrades for the 320, integrated as standard components.

You won’t need to buy these separately. The design guarantees durability and comfort right out of the box, letting you install and use your toilet without extra seat or lid purchases.

Replacement parts remain available if needed.

What Is the Weight Difference Between Dometic 310 and 320 Models?

Picture a feather and a pebble: the Dometic 310 weighs about 41 lbs, while the 320 tips the scales at 37 lbs, making the 310 roughly 4 lbs heavier.

This difference mainly stems from bowl shape. The 310’s round, possibly thicker ceramic adds weight compared to the 320’s elongated bowl.

For you, this slight weight gap won’t affect installation much but might make handling the 320 a bit easier during setup or removal.

Can These Toilets Be Used With Composting or Alternative Waste Systems?

You can’t use these toilets with composting or alternative waste systems because they’re designed strictly as gravity-flush models requiring connection to a black water holding tank.

Neither 310 nor 320 supports separation of waste or composting technology.

Their flushing mechanisms and installation specs don’t accommodate composting setups, so you’ll want to choose specialized composting toilets for that purpose.

Are There Any Color Options Available Besides White for These Models?

You won’t find any color options beyond white for these models. Over 95% of Dometic toilets sold come exclusively in white or off-white.

Both the 310 and 320 use vitreous ceramic or porcelain bowls and seats typically finished in glossy white due to manufacturing norms.

Sticking with white guarantees compatibility and ease of replacement.

Maximize Comfort and Efficiency in Your RV Bathroom

When choosing between the Dometic 310 and 320, consider that the 320’s dual-flush mechanism reduces water usage by up to 30%, making it more efficient for extended trips.

You’ll appreciate the 320’s enhanced durability and comfort if space and installation allow. However, the 310 still offers reliable performance with simpler requirements.

Evaluating your RV’s space and water capacity will help you pick the model that balances efficiency, comfort, and longevity best for your needs.

Last update on 2025-11-10 / Affiliate links / Images from Amazon Product Advertising API