How to Remove Dometic 10 Gallon Water Heater from Class A RV (Without

The Quick Answer

SAFETY WARNING: Before beginning any water heater removal, ensure propane is completely shut off at the main tank valve and allow the system to cool completely. Work in a well-ventilated area and have a fire extinguisher nearby when working with gas connections. Always disconnect electrical power at the main panel before working on any electrical connections.

Your RV's Dometic 10-gallon water heater can absolutely be removed without pulling the refrigerator, and you're right to avoid cutting access holes if possible. The key is working from both the exterior compartment and interior simultaneously. You'll need to disconnect the propane line at the exterior fitting and carefully thread it through, then disconnect the water lines from inside the RV at their nearest accessible connections rather than trying to access them directly behind the unit. Many Class A motorhomes have enough flex in the plumbing lines to allow the heater to slide out sufficient distance once all connections are properly disconnected, though clearance varies by manufacturer and model. The water lines typically connect via flexible PEX or copper lines that have enough play to allow removal without refrigerator access.

Your situation is actually quite common with RV coaches from this era. The manufacturers often positioned the water heater directly behind the refrigerator to maximize interior space, but they designed the service access to work from the exterior compartment combined with strategic interior disconnections. The trick is identifying exactly which connections need to be made where, and in what sequence, to avoid the frustrating situation you're experiencing where the unit moves slightly but won't come free.

What's Causing This

Common causes of water heater removal difficulty include the integrated installation approach used in Class A motorhomes. Dometic designed these 10-gallon units to fit snugly into dedicated compartments with connections routed through specific pathways to maximize space efficiency. In many RV models, the water heater compartment was engineered to share space with the refrigerator cooling system, creating the tight quarters you're experiencing.

The water lines are most likely connected via a manifold system that routes both hot and cold lines through the floor or side wall of the water heater compartment, then connects to the main RV plumbing system somewhere near the galley area. These connections were typically made with flexible PEX tubing or copper lines with enough service loop to allow for removal, but only when disconnected at the right points. The propane line follows a similar pattern, entering through the exterior wall and connecting to the main LP system, usually with a shutoff valve accessible from inside the coach.

What's happening is that you're trying to remove the unit with the water lines still connected at their primary junction points, which creates tension that prevents the heater from sliding out far enough to access the rear connections. The electrical connections, typically 12V DC for the ignition system and potentially 120V AC if equipped with electric heating elements, also need to be disconnected at accessible points rather than at the unit itself.

The leak you're experiencing is commonly occurring at several failure points on these Dometic units. The tank itself may have developed a pinhole leak due to anode rod depletion, the temperature and pressure relief valve may be weeping, or the inlet/outlet connections may have loosened over time. Before committing to a full removal, it's worth trying to access these components for inspection once you get the unit moved out slightly further.

Tools You'll Need

For this water heater removal project, you'll need a comprehensive set of tools to handle both plumbing and electrical disconnections safely. Start with a good set of wrenches including adjustable wrenches in 8-inch and 12-inch sizes, along with a complete set of combination wrenches from 7/16-inch up to 3/4-inch. The propane connections typically use 3/8-inch flare fittings, while water line connections vary depending on whether they're compression fittings, threaded connections, or PEX crimp fittings.

You'll need specialized plumbing tools including PEX cutters if your lines use PEX tubing, pipe wrenches for any threaded steel connections, and a basin wrench for accessing connections in tight spaces. A good quality tubing cutter will be essential if you need to modify any copper lines during the process. Don't forget channel lock pliers in multiple sizes for gripping various fittings and connections.

Electrical work requires wire nuts, electrical tape, a multimeter for testing connections, and wire strippers. You should also have a non-contact voltage tester to ensure 120V power is disconnected before working on any electrical connections. A flashlight or headlamp is absolutely essential given the tight working conditions, and a magnetic parts tray will help keep track of fasteners and small components.

Safety equipment includes safety glasses, work gloves, and a drop cloth to protect the surrounding area from water spillage during disconnection. Have several containers ready to catch any residual water from the lines, and keep absorbent materials handy. A camera or smartphone is invaluable for documenting connection locations and wire routing before disconnection, making reassembly much easier whether you're reinstalling the same unit or upgrading to a tankless system.

Step-by-Step Fix

Begin by completely draining your water system using the water heater's drain plug or drain valve, and relieve pressure from the water heater tank by opening the temperature and pressure relief valve and turning off all power sources including the main battery disconnect and shore power. Remove the exterior access panel and locate the propane shutoff valve, which should be accessible from inside the RV near the galley area. Close this valve and allow the system to cool completely if it has been recently operated. Take photos of all visible connections before beginning any disconnection work.

Working from the exterior access panel, identify the propane line connection at the water heater. This is typically a flare fitting that can be loosened with the appropriate wrench. Before loosening, mark the fitting orientation with a permanent marker to ensure proper reassembly. Slowly loosen the connection, allowing any residual gas to escape safely. Once disconnected, you should be able to push the propane line and fitting back through the exterior wall opening, giving you the clearance you've been seeking.

Turn off the water pump and open a faucet to relieve line pressure before proceeding. Next, locate the water line connections inside the RV. These are typically found under the kitchen sink, in a basement storage compartment, or behind an access panel near the galley. Look for flexible water lines that route toward the water heater area. The hot water outlet usually connects to the main hot water distribution manifold, while the cold water inlet connects to the main fresh water system. Disconnect these at the most accessible junction points, not necessarily at the water heater itself. Mark each line clearly to avoid confusion during reassembly. When reconnecting propane lines, always test all connections with soapy water solution to check for gas leaks before operating the system.

The electrical connections require careful attention in your RV. The 12V ignition system typically connects through a junction box accessible from inside the RV, often located in the same area as the water line connections. Disconnect these wires at the junction box rather than at the unit itself. If your water heater has 120V electric heating capability, this connection usually terminates at a dedicated circuit breaker and should be disconnected at the electrical panel after confirming power is off with a voltage tester, ensuring the breaker is turned off.

With all utilities disconnected at accessible points rather than at the unit itself, return to the exterior access panel and attempt to slide the water heater out. You should now have sufficient clearance to move the unit out from the compartment for service or replacement, allowing access to the rear connections for inspection or complete removal. The flexible utility lines should provide enough service loop to accommodate this movement without strain.

If you discover the leak is repairable, common solutions include replacing the anode rod if the tank shows corrosion damage, replacing the temperature and pressure relief valve if it's weeping, or tightening loose inlet/outlet connections. For tank replacement, measure the exact dimensions of your compartment opening and water heater space to ensure your chosen replacement unit will fit properly. Tankless units often require different mounting configurations and may need modifications to gas and electrical supply systems.

During reassembly, reverse the disconnection process but pay special attention to torque to manufacturer specifications on all connections. Propane fittings should be tight enough to seal without overtightening, which can damage the flare surfaces. Test all connections with soapy water solution before returning the system to service. Water line connections should be snug but not overtightened, as excessive force can crack PEX fittings or compress copper tubing.

Before sliding the unit back into position, test fit everything to ensure proper clearance and alignment. Apply fresh pipe thread compound to any threaded connections and use new compression rings if working with compression fittings. Once the unit is back in position and all connections are complete, restore power and water pressure gradually while checking for leaks at all connection points.

When to Call a Pro

Consider calling a professional RV technician if you encounter propane line modifications that go beyond simple disconnection and reconnection. Working with LP gas systems requires specific knowledge of pressure testing, proper flare fitting techniques, and safety procedures that can have serious consequences if performed incorrectly. If your propane lines show any signs of damage, corrosion, or if you're uncomfortable working with gas fittings, professional installation ensures safety and compliance with RV industry standards.

Electrical work involving 120V connections, especially if modifications are needed for a tankless system upgrade, often requires professional installation to meet local electrical codes. Many RV parks and campgrounds require proof of professional installation for major electrical modifications, and insurance considerations may also come into play. If your water heater removal reveals unexpected electrical configurations or if you're planning to upgrade to a system with different electrical requirements, professional consultation can save time and ensure safety.

Complex plumbing modifications, particularly if you're switching to a tankless system that requires different water flow rates, pressure requirements, or mounting configurations, benefit from professional expertise. Tankless units often need specific venting requirements, different gas pressure settings, and precise water flow calculations that can be challenging for DIY installation. A professional can also assess whether your existing propane system has adequate capacity for a tankless unit's higher BTU requirements.

Finally, if removal reveals structural issues with the water heater compartment, such as water damage to surrounding materials, compromised insulation, or signs of carbon monoxide exposure around the combustion area, professional assessment becomes critical. These issues extend beyond simple water heater replacement and may indicate larger problems that require comprehensive repair to ensure safe operation of your RV systems.