RV Water Heater Not Working? How to Troubleshoot Gas, Electric, and 12V Problems
- Start Here: Quick Checks Before You Troubleshoot
- Not Working on Electric? Check 120V Shore Power and 12V Control Power
- Keeping Lights, Phones, and Wi-Fi Going While the Heater Is Down
- Not Working on Gas? Propane Supply, Ignition Lockout, and the ECO Reset
- What the ECO does and why it trips
- Drips, Leaks, Smells, and the Anode Rod
- When to Call an RV Technician, and Safety Checks for Every Owner
- Conclusion
- FAQs
Few things end a camping day faster than a cold shower in the RV. The good news is that an RV water heater not working often comes down to something simple. A switch may be off, the bypass valve may still be set from winter, the tank may be empty, or the propane valve may be closed. Other problems, like a burner that keeps locking out or a gas smell, belong with a trained RV technician. This guide sorts the two using steps from Suburban and Dometic owner manuals, so you know what's safe to check yourself.
Start Here: Quick Checks Before You Troubleshoot
Before you suspect a bad part, make sure the heater is set up to make hot water at all. Most RV tank heaters run on propane, 120V electric, or both, with a switch for each mode. The brand and model are on the label behind the outside access door.
Four Things to Check First
Suburban and Dometic (formerly Atwood) are the common brands. A Suburban SW6D is gas only, while an SW6DE runs on both. These checks apply whether it's a camper water heater not working or a motorhome unit.
Is the right mode on? On Suburban gas/electric models, the 120V switch sits "behind the water heater door in the lower left corner of the control housing," apart from the gas switch inside.
Is the tank full? Suburban says the tank must be filled before you run the heater. Open a hot faucet until water flows with no sputtering air.
Is the bypass still set? A bypass kit closes off the heater for winter so antifreeze stays out. Left in bypass, the heater can't heat your water, so check your RV manual for valve positions.
Has it had enough time? Heat-up time varies, so check the manual's recovery rating.
Match Your Symptom to the Right Fix
An RV hot water heater not working in only one mode is a useful clue. This table points you to the right section.
Symptom | First things to check | Section |
No hot water in any mode | Switches, full tank, bypass position | This section |
Works on gas, not electric | Shore power, element switch, breaker | Electric and 12V |
Works on electric, not gas | Propane level and valve, red reset light | Gas side |
Neither mode, no ignition sound | 12V power and fuse | Electric and 12V |
Water drips from the relief valve | Normal expansion vs. a real fault | Leaks and drips |
Hot water in an RV is limited. Once the heater works again, tips for hot showers in an RV help a 6 or 10 gallon tank go further.
If the switches, water, and bypass check out, look next at power. That means both the 120V side and the 12V controls.
Not Working on Electric? Check 120V Shore Power and 12V Control Power
An RV water heater can depend on two kinds of electricity. The 120V AC side heats the element when you're on shore power or a generator. The 12V DC side runs the controls and spark ignition, even when you're heating with propane. So when you're dealing with an RV water heater not working on electric or gas, the cause often sits in one of these two circuits.
The 120V element side
A search for "RV hot water heater electric not working" usually leads back to the power supply. A Suburban SW6DE label, for example, lists a 120V, 1,440 watt element that draws 12 amps. Is the RV on shore power or a running generator? Is the element switch on, and has the water heater breaker tripped?
Never switch on the element with an empty tank, since Dometic warns a dry element can burn out and void the warranty. Meter testing, element swaps, and wiring go to your dealer or a qualified service person, as Suburban advises.
The 12V control side
Dometic recommends powering the heater from a 12V battery or the filtered side of the converter. If the fuse is good and the unit still won't run, it says to check for voltage above 14 volts. Suburban recommends a converter wired in parallel with the battery for steady voltage.
Check that the house battery is charged, the disconnect is on, and the heater's fuse is intact. Replace a fuse only with the rating on the panel or in the manual, never a bigger one. A weak battery can stop gas operation too, because the spark ignition needs 12V.
Many electric-mode problems start at the campground pedestal, not the heater. Knowing how RV shore power works makes it easier to rule out a tripped pedestal breaker first.
Even a simple fix can take a day or two if you're waiting on a part or a technician. It helps to plan for the basics.
Keeping Lights, Phones, and Wi-Fi Going While the Heater Is Down
Troubleshooting often happens at night, at a dry site, or while you wait on a mobile tech. A standalone battery can run a lamp, charge phones, and keep a router online without touching the RV's wiring. It won't heat water, and it should never be connected to the heater or the RV's electrical system.
A Separate Battery for Small Loads
With the heater off while you wait, you still need light to work by and a phone to call for help. EcoFlow's DELTA 3 line is built for separate, plug-in use at a campsite, and the EcoFlow DELTA 3 Classic is sized for small loads like lamps, phones, and a router.
How Long Could It Run Your Basics?
For a planning estimate, use 1,024Wh × 0.85 ÷ load in watts. The 0.85 is an assumption for conversion losses, not an EcoFlow rating. An LED lamp, a router, and phone charging at about 30W come to roughly 29 hours. Add a laptop for about 60W, and it's roughly 14.5 hours.
These are estimates, so check the watts on your own devices. Keep the unit dry and away from the heater compartment, propane lines, and any dripping relief valve.
A router on battery keeps remote workers on schedule, too. The basics of working remotely from an RV still apply when the coach is waiting on a part.
If the electric side is fine but the heater won't light on propane, turn to the gas side. It has its own short list of checks.
Not Working on Gas? Propane Supply, Ignition Lockout, and the ECO Reset
On propane, the controls try to light the burner a few times, then stop if no flame is sensed. That lockout is a safety feature, not a failure. You can check the fuel and reset it, but burner and gas valve work belongs with an RV technician.
Check the Propane Supply First
First, make sure the tank isn't empty and its valve is open. If running the RV fridge on propane works fine, the tank and main valve probably aren't the problem. On a first startup, Suburban notes it may take several ignition cycles to purge air from the gas lines.
How to Reset an Ignition Lockout
Reset steps depend on the brand. This motorhome hot water heater troubleshooting works in trailers too:
Suburban: A red "RESET" light stays on after the ignition tries. Turn the switch off, wait five seconds, and turn it on. If it still won't light, call a Suburban service center or RV service agency.
Dometic: If the light stays on more than 15 seconds, switch off, wait 5 minutes, and retry. After a high-temperature lockout, let the water cool and switch off for at least 30 seconds. If the lockout continues, contact a Dometic Service Center.
What the ECO does and why it trips
The energy cut-off (ECO) shuts the heater down if the water overheats. On Suburban SW models, you push a reset grommet for the gas side (A) or electric side (B), and the water must be below 110°F first. Dometic says to find and fix the cause of overheating before resetting.
One trip can be reset, but repeated trips mean it's time for a technician. Check the door screen for debris, too. Suburban says soot signals incomplete combustion, so shut the heater off and call a pro if you see it.
If you smell propane: Get everyone out of the RV and shut off the gas at the tank. Don't touch electrical switches, use a phone or radio inside, or start the engine or generator. Call your gas supplier, a qualified technician, or the fire department, and call 911 if anyone feels ill. Keep the gas off until the leak is repaired.
Some problems show up as water instead of temperature. A few of them are completely normal.
Drips, Leaks, Smells, and the Anode Rod
A wet compartment doesn't always mean a failed part. RV water systems are closed, so heated water has to expand somewhere. Knowing which drips are normal saves you from replacing a good valve.
When a Relief Valve Drip Is Normal
Suburban's pressure-temperature (P&T) relief valve opens at 210°F or 150 psi. Some dripping as the water heats is normal, and Suburban says it "does not indicate a defective relief valve." To restore the air pocket at the top of the tank:
Turn off the heater and let the water cool, or run hot water until it is cool. Then turn off the cold water supply.
Open a hot faucet.
Pull the P&T valve handle until water stops, then release it.
Close the faucet and turn the cold water back on.
Dometic gives a similar air-pocket procedure. Never plug or cap the relief valve, or put a valve between it and the tank.
Anode Rod Care and Freeze Protection
Suburban steel tanks also use an anode rod, which Suburban says to replace yearly or once it's more than 75% consumed. Not every brand's tank uses one, so check your manual.
Cold weather brings its own RV water heater problems. Suburban says to drain the heater or use RV antifreeze per the RV maker before freezing weather. Anyone taking on RV living during the winter should plan for this before a hard freeze. Leaks from the tank body, weeping fittings, or a cracked tank go to a technician.
Once the owner checks are done, anything left points to a technician. A few safety checks belong on your list too.
When to Call an RV Technician, and Safety Checks for Every Owner
Suburban and Dometic both say repairs should be done by a qualified technician. Owners can reset, refill, and check supplies, but the burner, gas valve, and wiring are jobs for a pro.
Signs You Need a Technician
Not every case of RV hot water not working is a DIY job. Call a technician when:
You smell gas, or see soot around the vent or burner.
The burner locks out again after a reset, or the ECO trips more than once.
The element won't heat on 120V after the shore power, switch, and breaker checks.
The tank or fittings leak, or a mixing valve needs replacing.
Carbon Monoxide and Recall Checks
The CDC's carbon monoxide basics say to have your water heater and other gas appliances serviced by a qualified technician every year. The CDC also recommends battery-operated or battery backup CO detectors near every sleeping area, replaced as the maker directs or every 5 years. It describes CO symptoms as often "flu-like," including headache, dizziness, weakness, and confusion.
If you suspect CO poisoning, CPSC's carbon monoxide guidance says to get to fresh air right away and then call 911. Run any generator outdoors, more than 20 feet from windows, doors, and vents, as the CDC advises. CPSC's carbon monoxide safety tips add that the exhaust should face away, which at camp means away from neighboring rigs too.
You can check for open safety recalls on your motorhome, trailer, or equipment with NHTSA's recall lookup tool. Adding the heater's switch, bypass, and door screen to a pre-trip RV inspection checklist catches most problems at home instead of at camp.
Conclusion
Most RV water heater trouble starts with the basics: the switch and mode, a full tank, the bypass, propane, and 12V or shore power. A reset is fine once, as your manual describes. Keep that manual in the RV, test your CO detector, and call a technician for gas smells, soot, repeat lockouts, or electrical repairs. While you wait, the EcoFlow DELTA 3 Classic can run lights, phones, and Wi-Fi from its own outlets, separate from the RV's wiring.
FAQs
Why is my RV water heater not working on electric but works on gas?
The 120V side usually isn't getting power. Check shore power, the element switch, and the breaker, and if those are fine, have a technician test the element.
Why does my RV water heater keep shutting off?
A burner lockout or an ECO that keeps tripping is the usual cause. Reset once as your manual describes, then have a technician find the reason if it happens again.
Where is the reset button on an RV water heater?
It depends on the brand. Suburban SW models have ECO reset grommets behind the outside access door, and many units reset the ignition when you switch them off and on.
Is it normal for an RV water heater to drip from the relief valve?
Suburban says some dripping while the water heats is normal in a closed system. Restoring the air pocket usually helps, but a steady stream needs a technician.
Can I run an RV water heater without water in it?
No. Suburban and Dometic both say the tank must be full before you turn on gas or electric, and a dry element can burn out.
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