RV Water Heater Not Working? 7 Causes and Fixes
Quick Answer
Before assuming your water heater is broken, check that shore power is connected, breakers aren't tripped, your propane tank has fuel, and your thermostat is set above 120°F. Then confirm your heater is turned on. Most complete failures are caused by tripped breakers, empty propane tanks, or control boards that need a power reset.
When your RV water heater stops working entirely, the troubleshooting can feel overwhelming. You might not know if it's a power issue, propane problem, or something inside the unit. This guide breaks down the seven most common reasons your heater has gone dark, with clear diagnosis steps and fixes you can try right now. Some solutions take 5 minutes; others require professional help. By the end, you'll know exactly what's wrong and whether you can fix it yourself or need a technician.
No Power or Tripped Breaker
This is the #1 reason RV water heaters stop working, and it's the easiest fix. Most RV water heaters require electricity to run the control board and igniter, even if they're set to gas mode. Start by checking your main breaker panel (usually near the entrance or in a basement compartment). Look for a breaker labeled "Water Heater" or "Hot Water"—if it's in the middle (tripped) or off, flip it back to on. If it stays on, you're done; turn the heater back on and wait 10 minutes for heating to start. If the breaker trips again immediately when you flip it, there's an electrical fault inside the heater and you need professional service. Also check that your RV is connected to shore power: if boondocking on battery, make sure your batteries are charged (voltage should be above 12V). Low battery voltage won't power the control board. Try plugging into 120V shore power at a campground or gas station for 30 minutes to confirm if that fixes it. If shore power works but batteries don't, your battery bank is depleted and needs charging before the heater will function.
Propane Supply Issue or Tank Empty
If your heater is set to gas mode (or Auto mode), it won't ignite without propane flowing. First, check your propane tank gauge on the RV exterior—if it reads empty or very low, that's your problem. Have the tank refilled at any propane station, or switch to electric mode if you have shore power and an electric heating element. You can test if propane is flowing by turning on a stove burner—if the stove lights, propane is flowing and your tank isn't the issue. If the stove won't light either, your propane tank is empty and needs refilling. However, if the stove lights but the water heater won't ignite, the propane line to the water heater might be blocked by a closed valve, a kinked hose, or debris. Check the supply line from the tank to the heater; look for any obvious blockage or damage. If the line looks fine, a closed isolation valve is likely culprit—ask a technician to trace the propane line and open any closed valves. In winter, propane can become sluggish in cold temps; if you're in freezing weather, warming the propane tank with blankets or heat lamps can help (never use open flames or direct heat). Always keep your propane tank above 1/4 full; below that, pressure becomes too low to ignite the heater reliably.
Pilot Light or Igniter Failure
If your water heater makes a clicking sound (igniter firing) but no flame appears, or if it makes no sound at all, the igniter electrode is likely corroded or broken. Start by listening closely: if you hear rapid clicking for 30 seconds and then it stops, the igniter is trying but failing. Open the access panel (usually at the bottom front of the heater) and look for the igniter electrode—it's a thin ceramic rod, typically white or cream-colored, positioned near the burner. If you see white crusty deposits on it, corrosion is blocking the spark. Gently clean the electrode with fine sandpaper or a pencil eraser, blow away all dust, and try igniting again. If the electrode is cracked or broken (you'll see a dark line through it), it needs replacement. If cleaning doesn't work and the electrode looks intact, the igniter transformer (part of the DSI board) might not be delivering spark to the electrode. This requires professional diagnosis and replacement. If you hear no clicking at all when trying to light, propane isn't reaching the igniter, the solenoid has failed, or power isn't reaching the igniter—all requiring professional service. Atwood and Suburban models are especially prone to igniter corrosion in humid climates; if you're near salt water or high humidity, plan to clean or replace electrodes every 1–2 years.
Thermostat Set Too Low or ECO Switch Tripped
This is embarrassingly common and not actually a failure. If your heater turns on but produces no hot water, check that your thermostat is set to at least 120°F (the minimum setting for most models). Look at the dial or digital display and make sure it's not pointing to 0°F or the lowest setting. If it's low, turn it up to 130°F and wait 5 minutes. The heating element or gas burner should turn on and warm the tank. Also check for an ECO (Eco/Economy mode) button or switch on the control panel—some models have a power-saving mode that limits heating or disables it entirely. If ECO is activated, press the button to turn it off. On digital displays, look for any warning lights or error codes; consult your manual if you see anything flashing. Finally, verify the heater is actually powered on—there should be a power switch or button on the control panel, and it must be in the "On" position. Sometimes a family member turns it off without telling you. Once you've confirmed the thermostat is set high and the heater is on, give it 30–45 minutes to heat a cold tank from scratch. If the tank still doesn't warm, move to other causes.
DSI Board or Control Board Failure
The DSI (Direct Spark Ignition) board is the brains of your water heater's ignition system. If this board has failed, you'll typically see one of these symptoms: no clicking when trying to ignite, control panel lights don't respond to button presses, or the heater turns on but does nothing. First, try a complete power reset: switch the heater off, turn off the breaker for the heater at your main panel, wait 30 seconds, then turn the breaker back on and switch the heater on again. Sometimes a power reset clears a temporary fault and the board recovers. If the board is truly dead, the control panel will be unresponsive and you won't see any lights or hear any fan sounds. The DSI board is a replaceable part ($200–$400), and if your heater is still under manufacturer warranty, you might qualify for free or discounted replacement. Check your warranty paperwork or contact the manufacturer (Atwood, Suburban, Dometic) with your serial number. If you're out of warranty, a technician can diagnose whether the board is dead and order a replacement. Don't attempt to repair the board yourself; water heater wiring involves 120V and propane, and mistakes are dangerous.
Anode Rod Corrosion and Tank Deterioration
The anode rod is a sacrificial metal rod (usually magnesium) that corrodes instead of your water heater tank, extending its life. If you've never serviced the anode rod, it may be completely corroded away, and your tank is now rusting from the inside. You won't see obvious external signs, but you might notice rust-colored water from your hot water tap or a weak water flow if rust particles are accumulating. Open the access panel on your heater and look for the anode rod—it should look like a rod or bolt. If it's mostly white crusty material or almost entirely gone, corrosion has consumed it and needs immediate replacement ($30–$60 part, $50–$150 labor). Replacing the anode rod now prevents pinhole rust leaks that would destroy the entire tank. If the rod is missing entirely (someone removed it and didn't replace it), rust is actively eating your tank. Install a new rod as soon as possible. If the tank has already developed pinhole rust leaks (you'll see steady water dripping from the bottom or sides), the tank cannot be saved and must be replaced. A new water heater runs $400–$1200 depending on brand and capacity. Most manufacturers recommend inspecting the anode rod annually and replacing it when more than half-corroded. This is cheap maintenance that extends tank life by years.
Complete Control Board Failure or Component Failure
If you've ruled out power, propane, igniter, and thermostat issues, the main control board or a critical component on it has failed. This might manifest as the display being dark, buttons not responding, fans not spinning, or the heater refusing to ignite despite all diagnostics showing the components should work. Control board failure is not DIY-repairable; the board must be replaced as a unit ($300–$500). Before replacing the board, a technician should confirm the failure using a multimeter, as a corroded connection or loose wire can sometimes mimic a board failure. If you're handy with a multimeter, you can test basic things: confirm 120V is reaching the board (touch your meter to the power connections), and confirm propane valve solenoid is getting power (meter should show continuity). If power isn't reaching the board despite the breaker being on, a wiring issue exists. If power is there but the board isn't responding, the board is dead. Warranty status matters here: if your heater is under warranty (usually 1–3 years from date of purchase), you might qualify for free board replacement. Check your paperwork and contact the manufacturer.
When to Call a Pro
Call a technician if you've confirmed power and propane are reaching the heater but it still won't ignite, if the DSI board or control board is unresponsive, if the igniter electrode is cracked and needs replacement, or if the tank is leaking or corroded. Board replacement and tank issues require professional expertise.
Frequently Asked Questions
Why does my water heater need electricity if it runs on propane?
Most RV water heaters use electricity to power the control board, igniter electrode, and propane solenoid valve. Even if your heater is set to gas mode, it won't function without electrical power (120V shore power or 12V battery). The actual heat comes from the propane flame, but ignition and control are electric.
Can I reset my water heater if it stops working?
Yes, you can try a complete power reset. Turn off the water heater, trip the breaker for 30 seconds, then restore power and turn the heater on. This sometimes clears temporary control board faults. If the reset doesn't work after 5 minutes, the fault is likely permanent and you need service.
How often should I replace the anode rod?
Inspect the anode rod annually and replace it if more than half-corroded. In most RVs with normal water chemistry, the anode lasts 3–5 years. Replacing it is cheap ($30–$60) and prevents expensive tank corrosion. Check after the first year to establish a baseline for your specific RV and water quality.
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Last updated: 2026-02-18