Welcome back to another Two-Minute Tech Tip Tuesday, brought to you by the National RV Training Academy—the largest hands-on RV training school in America. This week, instructor Sue Rasmussen, who leads the Advanced Water Heater and Furnace class, shares essential maintenance tips that every RV owner should know to extend the life of their water heater.
Whether you’re using a Dometic or Suburban water heater, these simple tasks can help prevent expensive repairs or premature failure.
Understanding the Dometic Drain Plug
Dometic water heaters are built with aluminum tanks and use a specific type of plastic drain plug. This component may look small and insignificant, but it plays a critical safety role.
The drain plug not only seals the tank but also acts as a pressure release if the water heater builds too much internal pressure. If other safety mechanisms fail, the plug is designed to soften and pop out, releasing pressure before the tank can rupture.
Using the wrong plug can be dangerous. Avoid replacing it with a metal plug, which can cause galvanic corrosion. When metal meets aluminum under pressure and heat, the plug may seize permanently in the tank. Also, generic plastic plugs from hardware stores often aren’t temperature-rated for RV use and should be avoided.
To remove the plug safely, use a shallow well socket (7/8 inch for Camco plugs, 15/16 inch for Dometic) and an extension tool for better access. Always let the tank cool first and open the pressure relief valve carefully to release internal pressure before removing the plug.
The Role of the Anode Rod in Suburban Water Heaters
Unlike Dometic models, Suburban water heaters have steel tanks, which are vulnerable to corrosion. To prevent tank damage, these systems use a metal drain plug with a built-in anode rod.
The anode rod is a sacrificial component designed to corrode over time, protecting the steel tank from deterioration. It should be inspected and likely replaced at least once per year—or more frequently in areas with hard water.
If an anode rod wears down too far, it no longer provides protection. Continued use of the water heater without replacing a deteriorated rod can lead to internal rust, pinhole leaks, and ultimately, complete failure of the water heater. Replacing the anode rod regularly is a small investment that can prevent a costly replacement.
Magnesium vs. Aluminum Anode Rods
There are two primary types of anode rods: magnesium and aluminum. Magnesium rods are standard and recommended in most cases. They are effective, affordable, and typically included with new Suburban water heaters.
However, there are two situations where an aluminum rod may be the better choice:
- If you regularly use very hard water, aluminum rods tend to last longer.
- If you notice a rotten egg or sulfur smell coming from the hot water only, the magnesium rod may be reacting with the water. Swapping it out for aluminum often resolves the odor.
If both hot and cold water smell, the issue is likely the campground’s water supply, not your water heater. Fortunately, you’re in an RV, and relocation is always an option.
Maintenance Checklist for RV Water Heaters
- Use only the manufacturer-recommended plastic drain plug in Dometic models.
- Avoid metal or hardware store substitutes.
- Inspect and replace the anode rod annually (or more often if needed).
- Use proper tools for removal and installation.
- Allow tank to cool and relieve pressure before servicing.
- Choose aluminum anode rods in specific hard water or odor-related situations.
Final Thoughts
These simple maintenance practices can dramatically extend the life of your RV water heater and ensure it continues to operate safely and efficiently. A little attention now can prevent major problems later.
If you have questions about your water heater, feel free to leave them in the comments—we may cover them in a future Tech Tip Tuesday. And if you’re ready to take your RV knowledge to the next level, consider enrolling in one of our hands-on training programs at the National RV Training Academy.
Need help from a certified technician or inspector? Go to rvhelp.com to find one near you.
There’s your Tech Tip.
Brought to you by the National RV Training Academy—where RVers become experts.