Suburban RV Water Heater Won’t Turn On [Quick & Proven Fix]

The most common reasons for a Suburban RV water heater won’t turn on include:

  • No water in the tank
  • Turned off 120V switch
  • Tripped circuit Breaker
  • Tripped reset buttons, etc.

In addition, electrical malfunctions and faulty heating element can prevent the heater from turning on as well.

In contrast, a Suburban gas RV water heater may not turn on if there’s not enough gas supply or the gas supply tube is blocked. Some other reasons for the gas RV water heater not turning on include:

  • Blown 12V fuse
  • Issues with the 12V battery
  • Tripped/faulty ECO/hi-limit thermostat, etc.

In this article, I’ll address every possible issue that might be preventing your RV water heater from turning and provide solutions to them.

So, keep on reading.

Suburban RV Water Heater Won’t Turn On

When your Suburban RV water heater fails to turn on, it can be frustrating. However, understanding the potential causes and solutions can help you resolve the issue promptly. Whether you have an electric or gas water heater, various factors may contribute to the problem.

For detailed Suburban RV water heater troubleshooting steps, follow the comprehensive solutions provided for electric and gas RV water heaters in the following sections.

i) Suburban Electric RV Water Heater Won’t Turn On

Many times, the Suburban Electric RV water heater won’t turn on because we leave the 120V switch off or turn it on without any water.

However, there are other reasons too. So, to make your life easier, I’m providing a table including all the common reasons along with their quick solutions first.

Probable Reasons For Suburban Electric RV Water Heater Doesn’t Turn OnQuick Solutions
No water in the tankFill the tank with water
Turned off 120V switchTurn the 120V switch on
Tripped circuit BreakerReset the circuit breaker
Tripped reset buttonsPress the reset button
Burned fusible linkReplace the fusible link
Faulty 120V switchFix or replace the 120V switch
Improper voltageCheck and ensure proper voltage supply
Shorted wires or improper groundingCheck and fix the shorted wires or improper grounding
Faulty heating elementReplace the heating element

So, how to fix the problem? Well, all you need to do is follow the step-by-step troubleshooting guide provided below. But make sure you follow the sequence as I’ve organized them from the easiest fix to the hardest fix.

01. No Water In The Tank

First things first, check if there is water in the water heater. Sometimes, the water heater may have been turned on when there is no water in it. This can cause the thermostat to trip off as the heater heats up the air quickly.

How To Fix:

To check if there’s water inside the water heater tank, you can do two things.

First, touch the brass valve labeled “P&T” (pressure and temperature) while the heater is on. If it feels warm, that means there’s water in the tank. Follow the below picture to identify the pressure relief valve.

suburban rv water heater pressure relief (p&t) valve

Second, if the heater has been turned off for a while, you can carefully open the valve to see if water comes out. If the water level is below the valve opening, you can remove the drain plug to check if water comes out.

If you find there’s no water in the tank, fill the tank with water and try restarting the water heater. But if the problem still persists, move on to the next troubleshooting guide I’ve provided below.

02. The 120V Switch Is Turned Off

The 120V switch should be turned “ON” for the electric water heater to function properly. If the switch is off, turn it on and check if the water heater is working.

suburban rv water heater switch location

The above picture shows the 120V switch location.

03. The Circuit Breaker Has Tripped

If the 120V switch is on and the water heater still isn’t working, check the circuit breaker to see if it has tripped. If it has, reset the breaker and try again.

However, if your Suburban RV water heater has the letter “D” (e.g. D, DE, DEL & DEM) in its model name, that means it has 12 volt DC operating system. In that case, there should be a 12-volt DC fuse. The electric element is powered by that fuse.

If the fuse is burned out, the electric element will not work. To fix this, replace the burned-out fuse with a new one.

04. The Reset Switch Has Tripped

Suburban RV water heaters have a reset switch that can trip if there is an issue with the heater.

If the reset switch is tripped, turn off the water heater and wait a few minutes before pressing the reset button. This should restore power to the electric element.

Also, to get detailed instructions about resetting your water heater you can check out our complete guide on how to reset Suburban RV water heater.

If the electric element is still not working, it may be due to a burned-out fusible link between the hi-limit and the thermostat. This link is designed to break in case of an overload. Examine the fusible link for any signs of damage and replace it if needed.

suburban rv water heater fusible links' location for 120 vac & 12 vdc

The above picture shows both the fusible links for 120 VAC and 12 VDC. If the 120 VAC link is broken/burned, your heater won’t work on electricity.

In most cases, the problem goes away with this step. However, you should follow the next steps if the heater still doesn’t turn on.

06. Faulty 120V Switch And/Or Faulty Connection 

Check the 120V switch and its connection. If the switch is faulty, it may not be able to turn on the electric element. To check if the switch is the issue, first, examine the connections.

Fix if you find any loose connection. You can also use a multimeter to test if it’s still functioning properly. If it’s not, replace it with a new one.

07. Improper Voltage

The electric element requires proper voltage to function properly. Make sure the voltage is within the manufacturer’s recommended range. For Suburban electric RV water heaters, it’s 120 volts. If it’s not, call a qualified electrician to fix the voltage issue.

You can use a multimeter to test the voltage of the thermostat and other components. 

08. Faulty Wirings 

If the voltage issue is fixed but the problem still exists, you should inspect the wiring for any signs of shorting or improper grounding. Repair or replace any damaged wires as needed.

09. Faulty Heating Element 

If none of the above solutions work, you might have a faulty heating element. So, check for the damaged heating element. The best solution for a damaged heating element is to replace it with a new one.

To replace the heating element in a Suburban RV water heater follow the instructions given below-

How To Replace The Heating Element

Step #1: First, turn off the power supply and allow the water to cool down.

Step #2: Once the water has cooled, drain the tank and remove the access cover and insulation.

Step #3: Use a wrench to remove the damaged heating element, making sure not to damage the tank or threads.

Step #4: Install the new heating element, making sure it is properly tightened and sealed.

Step #5: Refill the tank with water and turn on the power supply to test the new heating element.

By following these troubleshooting steps, you can identify and resolve the issue causing your Suburban RV water heater to not work on electric power. 

Always remember to follow safety precautions and consult a professional if you are unsure about any step in the process.

ii) Suburban Gas RV Water Heater Not Turning On

If your Suburban RV water heater is not working on gas, there could be several reasons as follows:

  • The electric heating element is on
  • Blown 12V fuse
  • Damaged 12V battery or low 12V battery voltage
  • Improper gas supply
  • Blocked gas supply tube
  • Turned off DSI/gas switch
  • Tripped/faulty ECO/hi-limit thermostat

Let’s look at the detailed troubleshooting guide for the Suburban RV water heater not working on gas.

How To Fix:

Step 1: First, turn off the electric switch. If the water is already heated, the propane thermostat won’t close to allow the burner to ignite. Wait for some time or let the water cool down before using the gas option.

Step 2: With cool water in the tank and gas supply, turn on the DSI/gas switch to the water heater inside the RV. The following picture shows a “turned-on” gas switch.

suburban rv water heater gas and electric on off switch

Listen for a clicking sound and check if the burner ignites. If the ignitor clicks, but the burner fails to ignite, move on to the next step.

Step 3: On the water heater’s face, locate the rubber cover near the top, which has two reset buttons that go to the ECO/hi-limit thermostats as shown in the picture below.

suburban rv water heater electric reset button and gas reset button

Press the right-hand side one for the 12-volt DC/gas ECO. If the ECO thermostat trips, you can press the button to reset it.

Step 4: If the problem still persists, check your 12-volt fuse inside your RV’s electrical panel to ensure it’s not blown. 

But how do you know if your suburban water heater fuse is blown?

If your Suburban water heater fuse is blown, you may notice that the hot water is not functioning.

To check if the fuse is blown, you can use a multimeter to test for continuity. Alternatively, you can visually inspect the fuse and look for signs of damage or discoloration. 

Step 5: If the fuse checks out, check the battery voltage and replace it if necessary. The following table shows the battery conditions and their respective course of action for your understanding.

Battery ConditionVoltage ReadingCourse of Action
Good Battery12.6V to 12.8VThe battery is in good condition
Bad Battery11V to 12.2VNeeds to recharge the battery
Dead BatteryBelow 10.5VNeeds to replace the battery

If your battery issue is solved, the water heater should turn on normally. However, if it doesn’t, follow the next step.

Step 6: Check that the propane cylinders have gas and are open. Turn on the gas stove burners to remove air from the lines.

Step 7: Inspect the two thermostats per side located beneath the rubber cover. The regular thermostat on the bottom of each side cuts power at 130 degrees. Whereas, the ECO/hi-limit thermostats on top cut power at around 160 degrees in case of regular thermostat failure.

The picture below demonstrates different thermostat types.

suburban rv water heater eco hi-limit thermostats and regular thermostats

If the ECO thermostat trips, you can press the button to reset it. If either thermostat is faulty, replace them as an assembly.

Step 8: Finally, check the burner tube for any blockages, like dirt or insect nests, before turning on the gas heater. Use a burner tube cleaning tool to remove any obstructions in the gas supply tube.


For Suburban RV water heaters refer to the owner’s manual for specific cleaning instructions and safety precautions.

It’s recommended to make cleaning the gas supply tube a regular habit, especially before taking your RV on a trip, to ensure the safety of your vehicle and family.

Your water heater should work just fine on gas by now. However, if the problem still persists, I recommend you call a technician for further diagnosis.


Why Won’t My Suburban Rv Water Heater Ignite?

Your Suburban RV water heater may not ignite due to a tripped circuit breaker, loose connections, or a faulty thermostat. Check these first before calling a professional.

Why does my RV water heater click but won’t start?

Your RV water heater might click but won’t start due to a faulty coil, clogged orifice, or malfunctioning valve. These parts can be repaired or replaced to fix the issue.

Can Rv Water Heater Run On Electric Only?

Yes, an RV water heater can run on electricity only. This is useful when connected to electrical hookups and helps conserve propane. When boondocking, an inverter is needed to convert DC power to AC power for the water heater to work.

End Note

In conclusion, when facing the issue of a Suburban RV water heater not turning on, you should consider various potential causes and solutions. 

For electric water heaters, factors such as a lack of water in the tank, a turned-off 120V switch, or a tripped circuit breaker could be the culprits. Additionally, electrical malfunctions or a faulty heating element may also prevent the heater from functioning.

On the other hand, gas water heaters may encounter problems due to insufficient gas supply, blocked gas supply tubes, blown 12V fuses, issues with the 12V battery, or malfunctioning ECO/hi-limit thermostats.

By addressing each of these possible issues, you can effectively troubleshoot and resolve the problem. Remember, regular maintenance of your Suburban RV water heater can help you avoid a lot of issues in advance.

Well, I hope this article has provided you with valuable insights and practical solutions for getting your Suburban RV water heater up and running again.

Finally, if your water heater does turn on but the water isn’t getting hot enough, read our comprehensive guide on Suburban RV water heater not getting hot enough.

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