So I've got a Suburban water heater with a cast iron tank and I'm thinking about adding electric capability. Problem is, most conversion kits I'm seeing want to replace the anode rod port with the heating element. That seems like a bad idea for a cast iron tank - pretty sure I need that anode rod to keep things from corroding, right?
Anyone know if there are kits out there that let you keep the anode rod? Maybe something that goes in the drain port instead, or one of those combo deals where the element also acts as an anode? Just want to make sure I'm not setting myself up for a rusty mess down the road!
To add electric heat while keeping the anode rod, look for kits that install in the drain port or use a combo anode/element. Avoid kits that replace the anode port entirely on cast iron tanks. The anode is critical for tank longevity.
Unfortunately, there aren't many higher-wattage electric conversion kits that maintain a separate anode rod like the Briidea system you found. The Briidea kit is indeed limited to 425 watts across all tank sizes - this isn't a sizing error in your search results. However, you have three viable options: stick with the 425-watt Briidea kit (which will work but heat slowly), look into magnesium anode rod elements that serve dual purposes, or consider the Atwood/Dometic conversion kits that use the heating element itself as a sacrificial anode. Your Suburban aluminum tank makes you a candidate for these approaches, though aluminum tanks require more careful consideration of galvanic corrosion.
The scarcity of high-wattage conversion kits with separate anode rods comes down to space constraints and electrical limitations in RVs. Most RV electrical systems can't handle elements above 1400 watts without significant upgrades, and fitting both a high-wattage element and a separate anode rod into the limited port space on RV water heaters is challenging. The 425-watt limitation on the Briidea kit is intentional - it's designed to work with standard inverter systems converting 12V DC to 120V AC and won't overload most RV electrical setups.
Suburban aluminum tanks require careful consideration of galvanic corrosion, which limits your conversion options. Most conversion kits eliminate separate anode rods, but using the heating element as a sacrificial component in aluminum tanks can accelerate corrosion.
The power limitation also relates to heating efficiency versus electrical draw. A 425-watt element will heat your 10-gallon tank in about 4-6 hours, which is acceptable for most RV applications. Higher wattage elements (1000+ watts) heat faster but require 120V shore power and can trip breakers if other appliances are running.
SAFETY WARNING: Before beginning any work, turn off power to the water heater at the main electrical panel and turn off the water supply. Allow water to cool completely before draining. Always verify power is off with a multimeter before handling electrical connections.
For the Briidea 425-watt conversion, start by draining your water heater completely and removing the existing anode rod. Check if your water heater has separate ports for the element and anode rod. If only one port is available, you'll need to use a combination unit or modify the installation according to manufacturer specifications.
If you want higher wattage, consider a dual-purpose magnesium anode element like those made by Camco or Suburban. These typically combine a 1400+ watt heating element with magnesium anode material. Remove your existing anode rod and install the combination unit in the same port. This gives you both heating and corrosion protection in one component, though the magnesium will need replacement based on water conditions and usage (typically 6 months to 3+ years).
For electrical connections, run dedicated 120V wiring from your electrical panel to the water heater location. Install an appropriately sized breaker following manufacturer installation instructions. Use marine-grade wiring and waterproof connections since this is in a potentially wet environment.
Test the system by filling the tank, checking for leaks, and monitoring the heating cycle. The 425-watt element heating rate will vary based on ambient temperature, tank insulation, and starting water temperature. Higher wattage elements heat proportionally faster. Install a manual switch or thermostat control so you can operate the electric element independently of any existing gas system.
Call a professional if you're uncomfortable working with both plumbing and electrical systems simultaneously, as this conversion involves both. If your RV's electrical system needs upgrading to handle higher wattage elements, that's definitely pro territory - upgrading inverters, adding circuits, or modifying the main electrical panel requires expertise to avoid fire hazards.
You should also get professional help if your water heater tank shows any signs of corrosion or if you discover the ports are damaged or corroded when you remove the existing components. A pro can assess whether your cast iron tank is suitable for conversion or if replacement makes more sense. Additionally, if you want to maintain any existing propane functionality alongside the electric upgrade, a certified RV technician should handle the integration to ensure proper safety controls and prevent conflicts between the two heating systems.
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