Dometic Sealand Traveler 111 to 511 Toilet Upgrade Guide

Tools & Parts Needed

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Quick Answer

Great news! The Dometic 511 is designed as a direct upgrade from the 111 model and will fit your existing 4-bolt floor flange perfectly. Dometic specifically engineered the 511 to maintain compatibility with older installations while providing improved features like better flushing performance and updated styling.

Why This Upgrade Works So Well

Dometic designed the Traveler series with backward compatibility in mind. Both the 111 and 511 models share identical mounting dimensions, bolt patterns, and basic plumbing connections. The 4-bolt floor flange pattern is standard across the entire Traveler line, which is exactly why this swap is so popular among RVers looking to modernize their facilities.

The main differences you'll notice are cosmetic and functional improvements in the 511: a more modern appearance, improved flush valve design, and better water distribution around the bowl. The footprint and mounting requirements remain unchanged.

What You'll Need

• New Dometic 511 toilet
• Adjustable wrench set
• Screwdriver set
• New wax ring or rubber seal
• Teflon tape for pipe threads
• Level
• Clean rags and disinfectant
• Nitrile gloves

Pre-Installation Preparation

Before starting, turn off your RV's water pump and water source (city water connection if connected), then drain the toilet's water supply line. You'll also want to empty your black tank - while not absolutely required, this is highly recommended for a cleaner, more sanitary installation process. Having good ventilation in your RV during this project is highly recommended.

Take photos of your current water line connections before disconnecting anything. While the 511 uses the same basic connection, having reference photos can save time during reassembly.

Step-by-Step Installation Guide

1. Remove the old toilet: Disconnect the water supply line (usually a quick-connect fitting or compression fitting). Remove the four mounting bolts securing the toilet to the floor flange. Carefully lift the toilet straight up and out - it may be heavier than expected, around 20-25 pounds.
2. Clean the flange area: Remove the old wax ring or rubber seal completely. Clean the floor flange thoroughly with disinfectant. Check that the flange is level and secure - now's the time to address any issues.
3. Install new seal: Place the new wax ring or rubber seal (included with your 511) onto the floor flange. Make sure it's centered properly.
4. Position the new toilet: Carefully lower the 511 toilet onto the flange, aligning the mounting holes. The toilet should sit level and rock-free. If it rocks, check that the flange is level and the seal is properly positioned.
5. Secure with bolts: Install the four mounting bolts finger-tight first, then gradually tighten in a cross pattern (opposite corners). Don't overtighten - you want firm contact but avoid cracking the toilet base.
6. Connect water supply: The 511 uses the same water connection as your 111, typically a 1/2-inch compression fitting or quick-connect. Wrap any threaded connections with Teflon tape. Hand-tighten compression fittings, then add 1/2 to 3/4 turn with a wrench.
7. Test the installation: Turn your water pump back on and test for leaks at all connections. Flush several times to ensure proper operation and check around the base for any water seepage.

Potential Minor Adjustments

While the toilets are direct replacements, you might encounter a couple of minor situations. If your water line is slightly short or the angle isn't perfect, you may need a short flexible connector or different elbow fitting. Most RV supply stores carry these common plumbing adapters.

The 511's flush mechanism operates slightly differently than the 111 - it uses an improved blade valve system that's more efficient. Don't be surprised if the flushing action feels different; this is normal and actually an improvement.

Benefits of This Upgrade

Beyond the direct compatibility, you're getting several improvements with the 511. The flush valve design provides better water distribution and more effective waste removal. The bowl design is also slightly improved for easier cleaning. Many RVers report that the 511 feels more substantial and less prone to developing leaks over time.

When to Call a Professional

If you discover that your floor flange is cracked, loose, or severely corroded during removal, stop and consult a professional. Flange repairs often require access from underneath the RV and potentially cutting into flooring. Also, if you find that your current plumbing uses non-standard fittings or has been modified significantly from original, a professional assessment might save you time and frustration.

Maintenance Tips for Your New Toilet

The 511's ball valve system benefits from occasional lubrication with RV-safe toilet seal lubricant. Keep the flush mechanism clean and avoid using harsh chemicals that can damage the seals. The improved design should give you years of reliable service with basic maintenance.

Consider upgrading to RV-specific toilet paper if you haven't already - it breaks down faster and reduces the chance of clogs, protecting your investment in the new toilet.