Most recreational vehicles come with water heaters to make it easy to access hot water when traveling the open road. However, RV water heaters can present a few problems preventing them from functioning efficiently like other electric appliances. Fortunately, an electric RV water heater doesn’t require much attention or expertise to fix.
Follow our detailed troubleshooting on electric RV water heaters to find solutions for the most common problems. While at it, we have provided essential maintenance tips and a basic operation overview to help you run your electric RV water heater properly.
How do I know if my RV water heater is gas or electric?
Although RV water heaters run on solar energy, gas, oil, and electricity, the most common water heaters operate by either electricity or gas. Similar to domestic water heaters, electric RV water heaters warm up the water when it comes in contact with large coils extending into the tank. In comparison, gas RV water heaters use a burner to heat the water in the tank. Before using or even troubleshooting your RV water heater, it is essential to understand what it runs on. The following instructions will help you identify what kind of water heater is in your RV.
The main difference between an electric RV water heater and a propane gas water heater in the mode of heating:
- Gas RV heater: These water heaters require you to ignite the pilot light manually. However, modern RVs with gas heaters have an automatic ignition that comes as a switch.
- Electric RV water heaters: These water heaters work when you have a 120-volt power source called shore power or a generator in your RV. They also have an electric thermostat that controls whether power is needed to heat the electric element or not.
- Combination water heaters: Some RV water heaters come with both electric and gas modes, which you can use separately or together when it’s convenient.
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Step one: Look for a blue flame pilot light.
Gas water heaters have a pilot light that indicates the presence of gas in your RV water heater. The electric water heater does not have a pilot flame.
Remove the access panel on the side of the water heater and look inside for a small blue flame.
Step two: Look for an electric supply cable.
An electric heater will have an electrical cord connecting the power source to the heater, black or gray.
Try finding an electrical cable at the top or side of the heater.
Step three: Look for a black or copper pipe.
A gas water heater will have a hose connecting the gas tank to the heater.
Look for a 5.5-inch black hose or 0.25-inch copper hose connecting to the bottom of the water heater, supplying gas to heat the water.
Step four: Look for a vent pipe or chimney.
A gas water heater has a vent pipe because it has a motor and fan inside that force exhaust created by the gas out through the vent pipe. Electric RV water heaters do not have a venting system as there is no exhaust.
Visually inspect your water heater. Search for a 3-inch or 4-inch PVC pipe connecting to the water heater.
Why is my RV water heater not working on electricity?
The most common issue you will encounter with an RV water heater is producing cold water. However, there are a few factors that explain why your water isn’t getting hot. Follow the steps below to troubleshoot the issue and get your water heater working.
- First, rule out any power problems. Begin by checking if the circuit breaker has any tripped breakers. Then switch on any tripped breaker in the fuse box and replace any blown-out fuses. A blown fuse will have a split filament or a darkened glass cylinder.
- Check if the bypass valve for 120-volt AC is off or on. The bypass valve winterizes the water heater, so you need to turn the valve to the off position.
- Press the reset button on your water heater until you hear it click into place. The reset button is located near the on/off switch or thermostat on the control panel.
- Check for any open faucets. Sometimes if more than one faucet is open simultaneously, cold water will flow out of one and hot water from the other. However, most RV water heater models are not large enough to have two open faucets at the same time while allowing hot water to flow from both.
- If no hot water is still coming out, switch off power to the water heater and check all wire connections. Look out for loose connections, corroded wires, and damaged cables. Make sure to tighten any loose connections, clean any corroded connectors with steel wool, or replace the wires if necessary.
- If the wiring is intact, check the temperature selector and reset the water temperature again.
- Check the handle on the bypass valve line. If the valve is open, you are bypassing the water heater, and no hot water will come out of the faucet. Close the valve to disengage the bypass.
- Check if the U-tube is blocked. Clean it to remove any blockage from the tube and burner, preventing water from heating adequately.
- Ensure the thermostat makes open contact with the aluminum tank for proper temperature monitoring. It should be set at HI and heat the water at 130 degrees. Replace the thermostat if it is defective.
- Lastly, test the heating element for continuity with a digital voltage meter if nothing works. Replace the heating element if it is defective.
How do you reset an electric RV water heater?
Electric RV water heaters have a reset button, a safety mechanism that interrupts current when there is a power surge or if the system overheats. The reset procedure for your RV water heater will vary depending on the model, but below is a general guide to resetting your RV water heater.
- Turn off the power to the RV water heater.
- Locate the reset button often near the thermostat or under a removable metal panel on the heater.
- Use a socket wrench to unscrew the nuts holding the thermostat panel cover at the back of the water heater, and then pull the cover away.
- Locate the red reset button protruding near the heating element.
- Push the reset button and release it when you hear it click into place. Note that some heaters do not click when you press the reset button. If there is no click after about five seconds, you can reassemble the heater and test if it restores hot water.
- If the reset button doesn’t stay retracted, wait for about 10 minutes and push it in place.
- Check if your RV water heater has two thermostats, then it most likely has two reset buttons. You will have to reset both buttons.
- Replace the panel cover on the back of the unit and screw in the nuts.
- Turn on the water heater.
- If the reset button trips again, there is likely an electrical issue that will require a professional to investigate and repair.
RV water heater is not getting hot enough.
If the water from your RV water heater is warm and not getting hotter, then the following reasons will help you fix the issue.
The thermostat temperature setting is correct.
The water heater in your RV has a thermostat that controls the water temperature. If someone changed the thermostat setting to lower temperatures, it could explain why your water heater is not producing hot water. You can fix this by simply turning the thermostat dial to your desired water temperature.
If the thermostat setting is correct and there is no hot water, it might be broken and need replacing.
Sediments on the heating element
Minerals from hard water will accumulate over time on specific components of your water heater, especially at the base of the water heater tank where the heating element is. The accumulation of the minerals on the heating element will affect its effectiveness and cause only lukewarm water. To fix this issue, ensure you flush your hot water tank annually to remove minerals from the tank. Also, to avoid recurrence of this problem, consider installing a water softening system in your RV.
Damaged dip tube
Cold water enters your RV water heater through the dip tube. Usually, the dip tube channels water directly to the bottom of the tank, where the heating element is to heat adequately. The faucets then come from the hot layer on top. However, if the dip tube is broken or damaged, it will direct the water to the top of the water tank, allowing cold water to mix with the hot water. And as a result, the water at the top will turn warm and come out of the faucet.
The water heater is breaking down.
Water heaters do not last forever. Most conventional RV water heaters can last approximately eight to twelve years, depending on brand and maintenance. However, over time, the components in your RV water heater will gradually wear, causing the unit to heat less efficiently and produce lukewarm water.
Size of the tank
Sometimes the size of the RV water heater can explain the lukewarm water. Most RV water heaters have a small capacity, which may prevent you from opening two hot water faucets simultaneously. One is likely to produce hot water, while the other may produce warm water. The solution is to use one tap at a time.
We advise against installing a larger water heater in your RV. However, upgrading to a tankless water heater will provide you with a constant stream of hot water.
Faulty heating element
Electric RV water heaters have two heating elements. If one heating element fails, your water heater will work half capacity. The functional heating element will only heat the water to warm rather than reach the thermostat temperature setting. If the water is constantly lukewarm, the upper heating element is faulty.
If there is a short supply of hot water with no lukewarm water, the problem is with the lower heating element. Either way, you will need to replace the heating element if it is defective with the help of a professional.
Regular servicing and maintenance will help avoid damage to the heating element.
RV water heater thermostat is not working
If you check your electric water heater carefully, you will notice two thermostats, one at the top and the other at the bottom. Each thermostat controls its heating element, which heats the water. Once you set the temperature on the thermostat, the water will heat up to that specific temperature, and the thermostat will shut off the heating element.
Therefore, if the thermostat goes bad, the circuit board won’t turn on the heat for the heater. If no hot water is coming from the hot water tap, the upper thermostat is likely faulty. But if the water comes out hot then becomes cold, then the lower thermostat is damaged. You will need to test both thermostats to identify the faulty one. Follow the instructions below to test an RV water heater thermostat and replace it.
- First, test the terminals with a voltage meter to ensure the thermostat receives power. You will have a reading of 240 on the power terminals. If there is no reading, check its power source.
- Then check the connection between the thermostat and circuit board. Wiggle the wires between the thermostat sensors and the control circuit board. If the light on the circuit board flashes on and off, you have a faulty thermostat. Another accurate way to test this is to wave a non-contact voltage tester near the top of the wires. If there are no lights or beeps on the tester, no electricity reaches the thermostat.
- Inspect the wires, also known as Emergency Cut-Off connectors, for loose or dirty terminals. If the connectors are loose, tighten them by squeezing them with a pair of needle pliers to ensure they fit snugly. If the terminal is dirt, clean them with dry steel wool or electrical cleaner, and if they are damaged, replace them. If the connectors are okay, check the Thermal Cut-Off fuse with a multimeter and replace it if it has blown.
- If the power source and connectivity to the thermostat are okay, test the thermostat sensors. If there is no continuity, replace the thermostats.
How to replace a faulty thermostat on an RV electric water heater
Replacing the thermostat in your RV water heater is pretty easy if you have the right tools. It’s important to note that even if one of the thermostats is faulty, you will have to replace both of them. Fortunately, the thermostat is relatively affordable. Follow the guide below on how to replace a defective water heater thermostat.
Things you’ll need
- Phillips screwdriver
- Non-contact voltage tester
- Switch off the power supply to the water heater, gas, and electricity. Confirm there is no power by testing the wires for voltage.
- Take out the panel at the back of the heater that covers the thermostat and heating element.
- Remove the insulation and avoid touching the wires.
- Test the terminal and wires using a non-voltage tester to ensure no current is in the thermostat.
- Take a picture of the connections on the thermostat to help you when connecting the new thermostat.
- Unscrew the terminals on the thermostat and pry out each wire.
- Then detach the thermostat from its holding clips. Finally, gently remove the thermostat from its chamber to prevent damaging the clips.
- Install the new thermostat into its corresponding clips, ensuring it rests correctly on the reservoir’s surface.
- Connect the circuit wires to the corresponding screw terminals and then tighten them.
- Adjust the temperature on the thermostat to your desired setting, which is usually about 120°F.
- Replace the insulation and panel cover.
- Switch on the circuit breaker and turn on the water heater electric switch.
How to turn on electric water heater in an RV
Starting an electric RV water heater is a relatively simple task. However, it may seem challenging for a beginner as you have to find the on/off switch. In addition, the location of the power button varies depending on brand and model. We’ll use the popular Atwood RV water heater to teach you how to turn on your electric RV water heater.
- Find the location of the water heater on your RV. It could also be on the back of one of the sides of your vehicle.
- Connect the water supply to your camper and allow the water tank to fill up with water. Always make sure the water tank is full before turning on the water heater.
- Confirm you have water in the water tank by opening a hot water spigot in your camper. Your faucet will sputter before running steadily, which will indicate the water heater is full.
- Ensure the water valves are in the proper position. Most campers have the winterizing valve and bypass valve. Turn both valves to the normal position.
- Go to the water heater monitoring panel and press the electric remote switch to turn on the water heater. The relay will close and run 110 VAC to the heating element.
- The heating element will cycle on and off as needed to heat your water. Therefore, you will not need to turn off the heater when not in use.
- If the electric remote switch stays on longer than 15 seconds, press the switch to the off position, wait about five minutes and repeat the previous step.
How to drain an RV water heater
One essential routine maintenance for your RV water heater is draining the system. Other reasons for draining the water heater include winterizing your trailer, troubleshooting the water heater, or storing your RV for an extended period.
Below is a detailed step-by-step guide on draining your RV water heater and some important tips to ensure you do not damage the heater in the process.
- Turn off the power supply to the water heater, electricity, and/or LP gas. For example, if your water heater has an electric operation, turn off the power switch. You can also turn off the breaker to the water heater because if the electric water heater mode is on with the tank empty, it will burn out the heating element prematurely.
- Disconnect the hot water bypass by turning the bypass valve to the standard position if you’re wintering the RV.
- Close off the water supply to the RV that is the water pump or city water supply.
- Open the hot water faucet inside the mobile home until the water runs cold.
- Allow the water in the tank to cool down and then open the water pressure valve to relieve water pressure. Keep the water pressure valve open when draining the water heater.
- Locate your water heater, typically in an outside compartment of your RV at the back or the side. You will see the drain plug in the bottom left-hand corner.
- Open the water heater drain plug. How you remove the drain plug depends on the brand of your water heater.
- Dometic RV water heaters (previously Atwood water heaters): This brand has a half-inch plastic drain plug. Take an adjustable wrench and loosen the plastic drain plug at the bottom of the water heater, and the water will flush out. Since the plastic is fragile and the corners can break during removal, we recommend having a spare drain plug in case it happens.
- Suburban RV water heaters: These water heaters have an anodized rod as the drain plug, which also protects the steel tank against corrosion by deteriorating first before the tank. Use a 1-1/16th inch socket to remove the rod and drain the water. Check the condition of the anode rod. If it is about 75% depleted, replace it with a new rod.
- Wait until all the water runs out of the water heater, and then replace the plug or anode rod when it’s empty.
- Close the pressure release valve.
- Attach an RV water heater tank rinser to a garden hose and turn the water on. Insert the water heater rinser into the drain plug and open the valve on the tool to flush out dirt from the water heater system. Flush the water heater for a few minutes or until the water comes out clean and clear.
How often should I drain my RV water heater?
It is essential to drain your RV water heater at the end of every season, and anytime you store the RV for more than two weeks. Otherwise, you risk the water becoming rancid and contaminated, which gives off a sulfur smell. The water heater’s stagnant water can also breed unhealthy bacteria if consumed and could damage components in your RV water heater. Popular RV water heater brands such as the Dometic water heater advise users to drain the systems regularly or at least once during the year.
How to fill an RV water heater
You have to fill your water heater tank if you’re about to use it for the first time or after winterizing before turning on your RV water heater. Starting the electric water heater with an empty tank leads to the heating element burning out too fast. Unfortunately, most water heater warranties do not cover damage or failure caused by operating the RV water heater with an empty or partially empty tank.
This process is the same for all RV water heater brands including, Dometic water heaters, Suburban water heaters, Jayco water heaters, Keystone water heaters, etc. It is also similar across all water heaters: gas-powered, electricity-powered, or both. Here’s how to correctly fill the water heater tank in your camper.
- Check if you have a bypass and/or drain on your water tank and close it before filling it.
- Open the shut-off valve on the cold water supply line.
- Slowly open all hot water faucets in your RV to allow the air to bleed out of the water heater system.
- There are two ways you can fill an RV water heater:
- First, use water pressure from the city water supply connected to your RV water line.
- Connect your RV fresh water hose to an outdoor hose coming from your home.
- Check the water tank and make sure it is complete.
- Open the water valve connection and fill the freshwater tank if necessary. Water from the city water supply will flow through the pipes into the water heater via water pressure.
- Once the tanks are full, disconnect the RV hose from the outdoor hose.
- Open the RV water heater panel and ensure the water heater’s water connection is secure.
- Pumping water into the heater from your freshwater tank:
- Connect the city water supply to the RV water heater inlet.
- Ensure the pressure relief valve is closed, the water heater is off, and there is no pilot light.
- Disconnect the propane gas tank from the water heater and switch off the electric control switch.
- Turn on the RV water pump, open a hot water faucet, and observe the water coming out of the tap.
- When the water stops sputtering and flows out in a continuous stream, turn off the RV water pump and close the faucet.
- Inspect the tank and water connections for signs of leaking. If there is any leakage, turn off the water pump and repair the damage.
- When the water pump turns off, and the tank is full, reconnect power to your water heater and turn it on.
How to clean and descale an electric RV water heater
Unfortunately, hard water is prevalent in most campground and RV parks where you can fill your RV water tank. Hard water contains calcium deposits which can turn your drinking water slightly salty and clog the water lines in your RV over time. That’s why cleaning and descaling your RV water heater is vital. The best time to clean and descale your RV water heater is when you won’t use your RV for at least two days. The guide below explains how to clean and descale the electric water heater in your RV.
Things you’ll need
- Six gallons of white vinegar
- Water softening tablets
- Garden hose
- Freshwater source
- Turn off all water supplies.
- Switch off gas and electricity. Disconnect the gas tank from the water heater.
- Open the drain plug or anode and drain the water heater.
- Flush out debris and sediment from the water heater tank using the rinser. Alternatively, you can turn the city supply on and flush loose dirt in the water heater. Then reconnect the water heater drain plug or anode rod.
- Leave the hose attached to the camper to divert the runoff to the ground.
- Use your RV camper winterizing kit to pour about 3-5 gallons of white vinegar into the water tank, depending on your water heater capacity. Then fill the rest of the water heater tank with water and close the valves.
- Turn on the electric heating element to heat the mixture for a minimum of eight hours. The heating of the vinegar solution allows it to remove all the scale build-up from the system properly. After eight hours, turn off the water heater and allow it to soak in the system overnight.
- After sitting overnight and cooling the water, open the drain plug or anode rod to drain the cleaning solution from the water heater.
- Flush the water heater system with clean water to remove any residue of the cleaning mixture, ensuring no vinegar smell. Then replace the drain plug or anode rod.
- Use a multi-purpose surface cleaner and a clean rag to wipe down all the components of your RV water heater while avoiding electrical wires and switches.
- Fill the water heater tank with freshwater or reconnect the water supply to the heater.
- Plug your propane gas tank into the RV water heater, and turn on the water heater switches.
How to bypass water heater in an RV
When winterizing your camper, the water heater tank does not risk freezing and expanding to damage your water heating system. However, your water lines are fragile and need winterizing, so the water heater bypass system is essential. The water heater bypass separates the water heater from the RV plumbing system, therefore, preventing antifreeze from flowing into the water heater tank when winterizing your RV water lines.
Bypassing your RV water heater is a more economical solution to winterize your water heater system. Instead of filling your entire RV water heater tank with gallons of antifreeze, you simply bypass your water heater system, so the antifreeze only goes into the water lines which require antifreeze.
- Find the bypass system of your RV water heater. The bypass valve system should be at the front of your water heater, accessible from inside your RV.
- Remove the access cover to the water heater. The cold water inlet is at the bottom, and hot water comes out of the top of the heater.
- Regardless of which type of bypass system you use, the basic water heater bypass design is a bypass pipe that connects the hot and cold water pipes are attached to the water heater.
- The valve lever should point in the direction you want the water to flow to engage the water heater bypass. This pipe will allow water from the cold water line to be routed directly to the hot water line without entering the water heater. In addition, you should turn both valves on the hot and cold water line to prevent the RV antifreeze from filling up the water heater tank.
- These are three common types of water heater bypass systems. But, first, you need to know which one you have to operate correctly.
- One valve bypass system: The valve is at the cold water line and the bypass line on this system. Turn the valve at the cold water line 90 degrees to the supply line to bypass the hot water tank.
- Two valve bypass systems: One valve is on the cold water inlet, and the other valve is on the bypass line. Turn both valves until they are parallel to the bypass plumbing line.
- Three valve bypass system: One valve is on the cold water inlet, the second is on the hot water outlet, and the third is on the bypass plumbing line. Turn the cold water and hot water valves perpendicular to the bypass line. Then turn the bypass valve until it is parallel to the bypass line.
- To disengage bypass mode and allow water or antifreeze to enter the water heater, reverse the position of the valve levers or knobs.
Note: Signs of improperly positioned bypass valves include:
- No hot water is coming from the water heater
- There is a short supply of hot water, which turns lukewarm quickly and then cold.
How often to replace RV water heater anode rod
Suburban RV water heaters have a short anode rod at the drain plug that protects the water heater from corrosion. The water tanks in Suburban water heaters are made of porcelain-lined steel prone to rust. Therefore, the anode rod acts like a sacrificial component that corrodes in place of the water tanks and pipes in your water heater. This means once the anode rod has depleted, the steel water tank will start to rust and corrode. Additionally, the anode rod also reduces the amount of sediment at the bottom of your tank, increasing energy consumption.
The anode has a relatively short lifespan. It tends to last between one to five years, mainly depending on your water quality and how much water flows through your water heater. You will need to replace this anode rod when it deteriorates to is half its original size. Inspect the condition of the anode rod at the end of every season to reduce the chances of a leak, improve your water quality and reduce RV water heater damage.
How to replace your RV water heater anode rod
Follow the guide below to properly replace the anode rod on your Suburban RV water heater.
Things you will need
- Six-point 1-1/16” impact socket
- Replacement anode rod
- Plumber’s tape
- Turn off the water supply, electricity, and gas to the water heater.
- Open a hot water faucet in your camper to drain some of the water and remove pressure from the system.
- Let the remaining water in the tank cool down before removing the anode rod.
- Go outside your RV and open the panel cover to the back of the water heater.
- Loosen the hex head and then use the socket wrench to pull out the anode rod from the back of the water tank. Sometimes, the anode rod may be too stuck. You may need a helper to hold the water heater while you pull the rod out.
- Wrap plumber’s tape around the joint threads of the new anode rod.
- Insert the anode rod into the drain and then tighten it by hand. Then use the socket wrench to tighten the rod more; however, do not overtighten it, such that the water heater starts to move or twist.
- After installing the rod securely, turn on the water supply to allow air to escape the water heater system.
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How to winterize an RV water heater
Winterizing your RV is necessary to preserve the life of your camper and save on repair costs. Generally, winterizing your RV water system means draining as much water as possible from the system and adding RV antifreeze to prevent any remaining moisture from freezing inside the system. Any water that freezes inside the water lines will expand and damage the pipes. Here’s a step-by-step guide to help you winterize your RV water heater correctly.
Things you’ll need
- 2-4 gallons of non-toxic RV antifreeze
- RV winterizing pump kit
- Water pump converter or clear tubing
- 1-1/16” impact socket
- Filter bypass kit(optional)
- Switch off your water heater’s water supply, propane gas, and electricity.
- Allow the water heater to cool down, then open the drain plug and pressure relief valve. Completely drain all the water from the water heater system and leave the drain plug open.
- Clean the inside of your water heater with an RV water heater rinser.
- Open all hot and cold water faucets in your RV and flush the toilet to remove any remaining water out of the system.
- Put your water heater bypass valve into bypass position to prevent the antifreeze from entering the water heater.
- If the RV water heater has a water filter, remove it and install a filter bypass kit to prevent the antifreeze from damaging the filter.
- Close all the faucets in your RV and replace all the drain plugs.
- Add antifreeze into your RV water system using one of the following options:
- Method one: Disconnect the suction side of the water pump and install a hose fitting onto the pump. Then insert the other end of the hose into a container of RV antifreeze, and it will flow into the RV.
- Method two: Install a T-bypass valve between the fresh water tank and water pump in the water lines. Run a hose from this T-bypass valve into your container of RV antifreeze.
- Method three: Take an antifreeze hand pump kit, insert the pump into the antifreeze container, and connect the hose into the city water inlet on your RV.
- After connecting the antifreeze, turn on the pump and run the antifreeze through the water lines to winterize your RV’s plumbing.
- Begin with all the highest and closest points to the pump, such as showers. Then open the hot and cold faucets until all antifreeze flows through the line. Repeat this process for all sinks, faucets, hoses, and toilets until you finish at the farthest faucet. Remember to also run the antifreeze through all external hoses and sinks.
- After running the antifreeze through your RV’s plumbing, shut off the water pump and open a faucet to release pressure from the system.
- Pour a cup of RV antifreeze down each drain in the bathroom and sinks.
- Turn the water heater bypass valve back to the normal position and reconnect the propane gas tank to the water heater. If your water heater has the electric mode, ensure the electric switch is off to protect the element when the RV is in storage.
We hope you can now operate and troubleshoot your electric RV water heater. Like other RV appliances, the water heater requires regular maintenance to function correctly and for longer. If you run into problems with your electric RV water heater, you can always refer to our article above for troubleshooting tips and general user instructions.