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Setting Your RV Water Heater to Electric Power: A Step-by-Step Guide

RV water heater settings can be confusing. Lots of new RVers are unsure about how to set an RV water heater to electric power. The steps are pretty simple. Usually, it’s just an on/off switch that needs flipping. In this article, we review the steps for turning on a Suburban or Dometic RV water heater from the switch.

RV Water Heater Basics: Suburban and Dometic Models

The Suburban and Dometic (formerly Atwood) companies are the two major manufacturers of RV gas / electric water heaters. Your RV probably has one of the two brands. Do you know how to find the switch(es) that control the operation of the electric element of the water heater? Now you will.

Setting Up the Suburban Model

A rocker switch controls the electric portion of a Suburban brand water heater. You will find it located at the bottom left of the water heater.

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Suburban Switch Combo to turn on electric RV water heater
Location of Suburban Switch & Cotter Pin

To access the switch, open the exterior access door and look just below the gas valve. A cotter pin might be inserted through the switch to prevent accidental activation, ensuring the water heater doesn’t turn on electrically when the tank isn’t full of water.

Pro Tip: Turning on the electric element with no water in the tank will result in the element burning out.

Inside the RV, look for an additional switch situated on the same faceplate as the DSI control, which manages the water heater’s switch to propane gas.

Activating the Dometic RV Water Heater on Electric Mode

To activate the electric heating function in the Dometic model, locate the switch inside the RV, as it is not mounted on the water heater itself. Instead, you’ll find this switch inside the RV. Much like with the Suburban model, the electric switch for the Dometic water heater is typically located on the same faceplate as the switch for changing the water heater’s fuel source to propane gas, commonly referred to as the DSI control.

Troubleshooting and Alternative Electric Power Tips

If the above Suburban and Dometic electric switch instructions do not result in 120 volts of electricity getting to your water heater, here are other steps to try.

  • Check the Power Source: Connect the RV to a working 120 VAC outlet to ensure power supply.
  • Inspect the Circuit Breaker: Locate and verify that the RV’s 120-volt circuit breaker for the water heater is on. You’ll find this breaker in the RV’s power distribution panel. Reset it if necessary.
  • Examine the Electrical Junction/Outlet Box: Look behind the water heater inside the RV for an electrical junction or outlet box.
    • In some RVs, the electrical side of the water heater actually plugs into a wall outlet.
    • In other RVs, check for an additional switch at the junction box connected to the water heater. Securely connect the plug and actively turn the switch to the ‘on’ position.
  • Make Sure the Thermostat and High Limit Switch on The Water Heater Haven’t Tripped: If they have, reset them.
T-Stat and Limit Resets
  • Navigate the ‘Either-Or’ Switch in Older RV Models: In older RVs, an ‘either-or switch’ lets you choose to direct shore power either to the microwave (or sometimes the air conditioner) or to the electric side of the water heater. This setup is necessary because a 30-amp power supply can’t run both at the same time. Manufacturers often place the either-or switch in a closet or another inconspicuous location for space efficiency.

Ensuring Safe and Efficient Use of Your RV Water Heater

If your water heater fails to operate on electricity after completing/checking all the above items? Then it’s time to call a qualified RV technician.  

Have the RV tech check for 120 VAC at all of the points mentioned and at the water heater element itself.

  • The presence of power at this component with no heat suggests it may be defective. The technician can then use a volt-ohm meter to check the component’s resistance; an abnormal result typically confirms a burnout.

For more insights on troubleshooting your RV water heater, refer to our detailed RV Water Heater Troubleshooting article.

Disclaimer: The instructions provided in this guide are based on common features found in many Suburban and Dometic RV water heaters. Your model may have different specifications or requirements. Always consult your water heater’s user manual or a professional technician for instructions tailored to your specific model to avoid damage to your system or voiding warranties.