Nothing ruins an RV trip faster than an unexpected cold shower. From my experience, those common Atwood RV water heater problems almost always boil down to simple issues with either the propane ignition system or the electric heating element.
This guide is your first stop for diagnosing the root cause—whether it’s a lack of spark, a tripped breaker, or a clogged burner—so you can get back to enjoying your adventure with hot water flowing again.
Your First Stop for Hot Water Headaches
When your RV's hot water suddenly disappears, it's easy to feel a bit overwhelmed, but don't panic. Most failures fall into predictable categories, and understanding the basics is half the battle. Atwood water heaters (now under the Dometic brand) are built with two independent systems: a propane-fueled burner and a 120V AC electric heating element.
Figuring out which system is failing is the key. If you have hot water when plugged into shore power but not when running on propane, you know the problem is with the gas and ignition components. On the flip side, if the gas works fine but the electric mode doesn't, you can focus on the electrical side—breakers, switches, and the heating element itself.
Understanding Your System
Before you start pulling things apart, it's crucial to know how each mode works. The propane system uses a 12V DC current from your RV's battery to power the control board, which then opens a gas valve and creates a spark to light the burner. The electric system, however, relies entirely on a 120V AC connection from shore power or a generator to heat the water with its own element.
You’d be surprised how many Atwood RV water heater problems are as simple as a hidden power switch being off or an empty propane tank.
A classic point of confusion for new RVers is the electric element's power switch. It's often a small, black rocker switch right on the face of the water heater, accessible from the outside panel. It’s incredibly easy to forget it's there.
This flowchart gives you a visual path for your initial check-up, starting with the basics of power and gas.
As you can see, troubleshooting should always begin with the most common failure points—power and fuel—before you dive into more complex components.
To help you get started even faster, here's a quick reference table. This is my go-to mental checklist when I first approach a water heater issue.
Atwood Water Heater Symptom and Cause Quick Reference
| Symptom | Potential Cause (Propane/Gas) | Potential Cause (Electric) | Initial Action to Take |
|---|---|---|---|
| No hot water at all (both modes) | Main propane valve closed | Main RV breaker tripped | Verify propane tank has fuel and is open. Check main 120V breaker. |
| Hot water on electric, but not gas | Empty propane tank, bad igniter/electrode, faulty control board | N/A | Check propane level. Listen for clicking/sparking at the unit. |
| Hot water on gas, but not electric | N/A | Tripped breaker, "hidden" exterior switch is off, burnt-out heating element | Check the breaker in the main panel. Find and flip the switch on the unit itself. |
| Pilot light won't stay lit | Blocked burner tube (spiders!), faulty thermocouple, low gas pressure | N/A | Clean the burner tube and thermocouple with compressed air. |
| Water is only lukewarm | Faulty thermostat/ECO, mixing valve issue | Faulty thermostat/ECO, bad heating element | Test thermostat continuity. Check for sediment buildup in the tank. |
This table should help you narrow down the culprit quickly so you know where to focus your efforts.
Initial Safety Checks are Non-Negotiable
Before you touch a single tool, let's talk safety. You’re working with propane and electricity, so caution is mandatory.
Always start by shutting off all power to the water heater. That means turning off the interior switches for both gas and electric modes and flipping the corresponding breaker in your RV’s main panel. Next, go outside and turn off the propane supply right at the tank.
This simple routine prevents accidents and gives you peace of mind. For those embracing the self-sufficient RV lifestyle, a functional water heater is non-negotiable. Our Practical Guide to Off Grid Living Essentials takes a broader look at keeping all your vital systems running smoothly.
Solving Propane Ignition and Burner Failures
It’s a classic RV problem: your Atwood water heater works just fine on electric, but switch it over to propane and… nothing. Just silence. When this happens, you can bet the problem is somewhere in the gas and ignition system. It's easily one of the most common Atwood RV water heater problems, but the good news is, it's often something you can tackle yourself with a little patience.
The signs can be anything from a total failure to light, to a weak, sputtering flame that covers everything in soot.
Fixing these issues means you have to trace the entire fuel path, from the propane tank all the way to the burner. Let's walk through the key components and figure out what’s gone wrong.
The Importance of Correct Gas Pressure
Before you start tearing parts out, first make sure you have enough propane pressure. This one thing can cause a whole host of other problems that look like more serious failures. For example, if you’re running the furnace and the stovetop at the same time, the demand might be too high for the system, starving the water heater of the fuel it needs to ignite and stay lit.
Propane pressure issues are behind a huge number of Atwood water heater failures. You need a minimum of 11 inches of water column (W.C.) for things to run right, and that becomes even more critical when multiple propane appliances are running at once. Low pressure leads to pilot lights going out, a jumpy main burner flame, and sooty buildup that kills efficiency.
I've seen RVers chase electrical "gremlins" for days, only to discover the root cause was an old, failing propane regulator. It’s a classic case of looking for a complex solution when the answer is simple.
Your RV’s propane regulator is the heart of your gas system. If it’s not delivering steady pressure, none of your appliances will work correctly. If you suspect pressure is the culprit, especially if your other gas appliances are acting up too, it's time to investigate. Our guide on how to troubleshoot and replace RV propane gas regulators is a great place to start.
Inspecting the Burner Tube and Orifice
One of the most frequent reasons for a no-flame situation is a blocked burner tube. Spiders and other insects love to build nests inside these tubes, blocking the flow of propane and air. This can stop ignition completely or give you a weak, yellow, sooty flame instead of the clean, blue one you want to see.
To check this, you'll need to pull the burner assembly. This usually means disconnecting the gas line (make sure the propane is off at the tank first!) and taking out a single screw that holds the burner in place. Once it's out, give it a good cleaning.
Here’s my go-to process:
- Use compressed air: Blast out the burner tube from both ends. This will dislodge most loose debris and spider webs.
- Use a flexible brush: For anything more stubborn, a pipe cleaner or a special burner tube brush will help scrape the insides clean.
- Inspect the orifice: The orifice is that tiny brass fitting where the gas comes out. Whatever you do, do not poke anything metal into it—you can damage it in a second. A quick shot of compressed air is all it should ever need.
A clean burner tube and orifice are the foundation for a healthy blue flame. You'd be surprised how often this simple bit of maintenance solves ignition problems.
Checking the Thermocouple and Pilot Light
If you have an older Atwood model with a standing pilot, the thermocouple is a vital safety component. Its job is to sense the heat from the pilot flame and tell the gas valve to stay open. If the thermocouple fails or gets caked in soot, it won't sense the flame and will shut off the gas, even if the pilot lights for a moment.
Take a close look at the pilot flame itself. It should be a steady, blue flame that completely covers the tip of the thermocouple. If the flame is yellow, weak, or seems to "lift" off the thermocouple, it's not getting hot enough. This is usually caused by a dirty pilot orifice or, again, low gas pressure.
If the pilot flame looks strong but the heater still won't stay lit, the thermocouple itself is likely bad. It’s an inexpensive part and fairly simple to replace, making it a logical next step in your troubleshooting. A clean, properly positioned thermocouple is the key to a reliable pilot light.
Troubleshooting the Direct Spark Ignition System
Modern Atwood water heaters run on a Direct Spark Ignition (DSI) system, which is basically the electronic brain that lights the propane burner. When it's working, you get that glorious hot water on demand. When it’s not, you’re usually met with frustrating silence, the promise of a cold shower, and a little red light that seems to be mocking you from the control panel.
This is probably one of the most common sources of Atwood RV water heater problems, but once you understand how it works, you're halfway to fixing it.
Instead of a pilot light that stays lit, the DSI system only creates a spark right when it's needed. When you flip that switch inside your RV, the control board initiates an ignition sequence: it opens the gas valve and tells the electrode to get sparking. If a flame doesn't ignite and prove its existence within a few seconds, the board smartly shuts the gas off and gets ready to try again.
This whole process repeats three times. If there's still no flame after the third attempt, the system goes into a "lockout" mode. This is a crucial safety feature that prevents unburned propane from building up. It’s also the exact moment the DSI FAULT light on your interior switch panel clicks on, letting you know something’s wrong.
Decoding the DSI Fault Light
That glowing red fault light isn't just there to annoy you; it's a diagnostic tool. It's the control board's way of saying, "Hey, I tried to do my job, but something stopped me." Your job is to figure out why it failed.
To get things going again, just turn the switch off for about 30 seconds and then flip it back on. This resets the control board, giving it a fresh start and kicking off another three-try ignition cycle.
If that light pops right back on after another failed cycle, you've confirmed there's a real problem. Electronic ignition failures are a frequent headache with these heaters. When a DSI system gives up after three tries, it's usually pointing to one of a handful of common culprits, like a bad thermostat, a dirty electrode, or a blown fuse on the control board. For more real-world stories on these issues, the forums over at Truck Camper Adventure are a great resource.
From my own experience wrenching on these things, people often jump to the worst-case scenario and assume the expensive control board is fried. Don't do that. The problem is far more likely to be a simple, cheap part like a corroded wire or a gunked-up electrode. Always, always start with the basics.
Let's walk through the most common points of failure, starting with the easiest ones to check.
Checking the Electrode and Thermal Cut-Off
The electrode wears two hats: it creates the physical spark to light the gas, and it senses the flame to tell the board the fire is lit. For it to do its job, it has to be perfectly clean and positioned just right.
Over time, carbon and soot build up on the metal tip, which can weaken the spark. The ceramic insulator can also crack. Just as important is the gap between the electrode tip and the burner—you're looking for a sweet spot of about 1/8 of an inch. Think of it like a spark plug in your truck; the wrong gap means a weak spark or no spark at all.
To check it, first make sure all power and propane are turned off. Then, gently clean the metal tips with a bit of fine-grit sandpaper or an emery board until they're shiny. Give the white ceramic a good look for any cracks and double-check that the gap is correct.
Another key player, and one that gets overlooked all the time, is the thermal cut-off. This is a tiny, one-time-use fuse sitting in a clear tube on a wire leading to the thermostat. If the burner chamber overheats—often because a mud dauber decided to build a home in there—this fuse blows, cutting all 12V DC power to the control board.
If your unit is completely dead (no clicking, no spark, and no fault light), the thermal cut-off is the very first thing you should inspect.
Testing the Thermostat and ECO
If your electrode looks good and the thermal cut-off has continuity, the next suspects are the thermostat and the ECO (Emergency Cut-Off). These are two separate sensors, usually bundled together and mounted directly against the water tank.
- Thermostat: This sensor is what tells the control board to kick on the heat when the water temperature drops below about 110°F.
- ECO: This is your high-limit safety switch. It cuts power if the water gets too hot (over 180°F) to prevent a dangerous pressure situation.
At their core, both of these are just simple on/off switches that should have continuity when the water in the tank is cold. You can easily test them with a multimeter set to continuity (the setting that beeps) or ohms. Just disconnect the wires from the terminals and touch your meter's probes to each one.
With cold water in the tank, you should hear a beep or see a reading close to zero ohms. If your meter reads "OL" (which stands for open loop), that component has failed and needs to be replaced. These sensors are a common failure point and, thankfully, a pretty cheap and easy fix.
Diagnosing Electric Heating Element Issues
Here’s a classic scenario I’ve seen countless times: your Atwood water heater works like a champ on propane, but when you switch over to shore power, you get a lukewarm—or downright cold—surprise. This is one of the most common Atwood RV water heater problems, and it almost always points to an issue with the 120V electric system.
The good news is that troubleshooting this is pretty straightforward. You're basically dealing with a simple circuit: power comes in, passes through a switch and a thermostat, and then heats up the element. The list of potential culprits is short, so we can track it down without too much fuss.
Start with the Simple Power Checks
Before you even think about grabbing a multimeter, let’s cover the basics. It’s amazing how often the problem is just a hidden switch or a tripped breaker.
Many RVers don't realize their Atwood heater has its own dedicated power switch, usually located on the unit itself and accessible from the outside access panel. I’ve seen people chase their tails for hours only to find this little switch was off. It's often small, black, and easy to overlook, but it must be on for the electric element to get power.
Once you’ve confirmed that switch is flipped on, head inside to your RV’s main electrical panel.
- Find the breaker labeled for the water heater.
- Flip it all the way off, then firmly back on. Breakers can sometimes look like they’re on even when they've tripped, so a good reset is always worth a shot.
These two checks solve a huge percentage of electric-side failures. If you want to get more comfortable with your RV's electrical system, our guide on troubleshooting RV electrical problems is a great place to start.
Testing the Heating Element with a Multimeter
If the switches and breakers are all good, it's time to test the heating element itself. This is the part that does the actual work of turning electricity into heat, and it's a common failure point—especially if it was ever accidentally powered on without water in the tank. Even a few seconds of "dry firing" can burn it out.
To do this right, you'll need a multimeter set to measure resistance (ohms, or Ω). First, shut off all 120V power to your RV. This is a critical safety step. Next, open the outside access panel, remove the protective cover over the heating element, and carefully disconnect the two wires from its screw terminals.
Now, place one probe from your multimeter on each of the element's screw terminals. An electric heating element for these Atwood water heaters should have a resistance reading somewhere between 9.6 and 10 ohms. These units can draw up to 1,500 watts, making them one of the bigger power hogs in your rig.
A multimeter reading of "OL" (Open Loop) or infinite resistance means the element is fried and the internal connection is broken. On the flip side, a reading of zero ohms means it has a direct short. Either way, the element is toast and needs to be replaced.
What to Do When the Element is Bad
Replacing a heating element isn't a tough job, but you have to do it in the right order. The absolute first step is to turn off the water supply and completely drain the tank by removing the drain plug. You don't want a flood on your hands.
Once the tank is empty, use a special element wrench or a large socket to unscrew the old element. Thread the new one in, making sure its gasket creates a good, tight seal. Reconnect the wires, and—this is important—completely refill the tank with water before you restore power.
If you power up the new element in an empty tank, even for a second, you'll burn it out instantly and be right back where you started.
Essential Maintenance to Prevent Future Problems
The best way to deal with Atwood RV water heater problems is to make sure they never happen in the first place. While knowing how to troubleshoot is a great skill, a solid maintenance routine is your best defense against those surprise cold showers and expensive repair bills. Just a few simple tasks each season can add years to your water heater's life and ensure it's always ready for your next adventure.
When you skip regular care, you're inviting problems like mineral buildup, corrosion, and worn-out parts that kill performance and efficiency. By sticking to a maintenance schedule, you're not just protecting your investment—you're making sure your water heater runs safely and reliably trip after trip.
Annual Tank Flushing for Peak Performance
One of the most important things you can do is flush the water heater tank at least once a year. Over time, minerals like calcium and magnesium—which are all too common in campground water—settle at the bottom of the tank and form a nasty layer of sediment.
This gunk acts as an insulator, making your heating element or gas burner work way harder to heat the water. That means you’re wasting electricity and propane. Even worse, that sediment can cause the tank to overheat, leading to a fried electric element or, in the worst-case scenario, a failed tank.
Flushing it out is pretty simple:
- First, kill all power (12V and 120V) and shut off the propane supply to the water heater. Safety first.
- Let the water cool down completely. Seriously, don't skip this step unless you enjoy getting scalded.
- Open the exterior panel and grab a socket wrench to remove the plastic drain plug.
- Stand to the side as the water gushes out. I highly recommend using a tank rinser wand hooked up to a hose; it does a fantastic job of blasting loose any stubborn crud at the bottom.
- Keep flushing until the water runs clear, then pop the drain plug back in.
Inspecting the Anode Rod to Prevent Corrosion
While many aluminum Atwood tanks don't have an anode rod, some of the steel-tank models do. This little part is a true hero. It’s a sacrificial piece of metal designed to attract corrosive elements in the water, essentially letting itself get eaten away to protect your steel tank from rusting out from the inside.
You’ll want to check the anode rod every year, usually when you're flushing the tank. If it’s more than 75% gone, looks like a skinny wire, or is caked in calcium, it's time for a new one. If you let a depleted anode rod go, you're risking a rusted, leaking tank—a problem that means replacing the entire water heater. To help prevent many of the issues discussed, and ensure the longevity of your unit, consider these essential water heater maintenance tips.
Here’s a classic mistake I see all the time: overtightening the anode rod when putting it back in. Just use some Teflon tape on the threads and tighten it enough to stop leaks. If you crank down on it too hard, you can strip the threads on the tank itself, turning a simple job into a massive headache.
Building Your Seasonal Maintenance Checklist
Consistency is everything when it comes to preventing Atwood water heater issues. Working a few quick checks into your regular RV routine will keep your system happy and healthy.
Here are the must-do items for your water heater checklist:
- Clean the Burner Tube: Before you head out for the season, give the burner tube a good look. Spiders and mud daubers absolutely love building nests in there, which blocks gas flow and leads to ignition problems or a sooty, inefficient flame.
- Test the Pressure Relief Valve: Once a year, gently lift the lever on the T&P valve. It should release a bit of water and then snap back into place. If it keeps dripping or won't close properly, replace it immediately.
- Check Electrical Connections: Do a quick visual inspection of all the wiring. Make sure everything is tight and free of corrosion, paying close attention to the grounds and the connections on the control board and electric element.
- Inspect Seals and Gaskets: Look over the exterior door gasket and any other seals. If they're cracked or worn out, replace them to keep water from getting into the component area where it doesn't belong.
Your Atwood Water Heater Questions Answered
Even after you've got the basics down, RV life has a way of throwing curveballs. When you're miles from home, a weird noise or a blinking light on your water heater can feel like a major crisis. I've been there. So, let's tackle some of the most common one-off questions and nagging Atwood RV water heater problems that pop up on the road.
Think of this as your quick-reference guide for those "what the heck is going on?" moments.
Why Does My Hot Water Smell Like Rotten Eggs?
That lovely sulfur smell is almost always from harmless bacteria setting up camp in your water heater tank. This is super common if you've recently filled your fresh tank with well water. The bacteria have a little party with the anode rod, and the result is hydrogen sulfide gas—the source of that rotten egg odor.
The fix isn't too complicated, but it does mean flushing your whole system. You'll need to drain and bypass the water heater, then sanitize your entire freshwater system. The go-to method is a diluted bleach solution (a good rule of thumb is 1/4 cup of bleach for every 15 gallons of tank capacity) run through all your lines.
Let that solution sit for a few hours, then flush, flush, and flush again with fresh water until you can't smell even a hint of bleach. Only then should you reconnect your water heater.
What Does the Blinking Red DSI Fault Light Mean?
That blinking red "DSI FAULT" light is your water heater's cry for help. It's telling you it tried to fire up the burner on propane and failed. For safety, the Direct Spark Ignition (DSI) system gives it three shots. If it doesn't sense a flame after the third try, it goes into "lockout" mode to keep raw propane from building up.
The first thing to try is a simple reset. Just flip the water heater switch inside your RV off, wait about 30 seconds, and turn it back on. This tells the control board to start a new three-try ignition cycle.
If that fault light keeps coming back, don't ignore it. It's a clear sign of a deeper issue. You could be looking at anything from a dirty electrode, a bad ground wire, low gas pressure, or even a failing control board that needs a closer look.
Can I Run Gas and Electric Heat at the Same Time?
Absolutely! On most Atwood models that have both, you can run them together, and it's a fantastic feature. Think of it as a "turbo" mode for your hot water. It's perfect for a much faster recovery rate, especially when you have a few people waiting to take showers.
The gas and electric systems are designed to work independently, each with its own thermostat, so you won't hurt a thing by using them at the same time. The only real catch is making sure your RV is plugged into proper shore power—a 30-amp or 50-amp service is a must to handle the heavy electrical draw from the heating element.
What Should I Do If My Pressure Relief Valve Is Dripping?
A dripping Temperature and Pressure (T&P) valve can be tricky because sometimes it's normal, and other times it's a warning sign. If you see just a little weeping during a heating cycle, that's often just the valve doing its job, releasing a bit of pressure as the water heats up and expands. No big deal.
But if that valve is dripping constantly, even when the water heater is off and the water is cool, you've got a problem. The valve's internal seat is likely gunked up with mineral deposits, or the valve itself has failed.
Here's a quick test: let the heater cool down completely. With city water connected, carefully lift the valve's little manual lever for a couple of seconds. This will shoot a burst of water through and hopefully clear any debris. If it still leaks after you let go, the T&P valve needs to be replaced. It’s a critical safety device, so a persistent leak is something you should never put off fixing.
When it's time for a repair, finding the right part shouldn't be another headache. For everything from heating elements and T&P valves to control boards, RVupgrades.com has a massive selection of components to fix your Atwood water heater problems and get you back to enjoying your trip. Find the exact part you need at https://www.rvupgradestore.com.
