RV water heater not heating water

Symptoms

• No hot water from any faucet
• Water heater switch is on but nothing seems to happen
• Pilot light won't light or keeps going out (propane models)

Likely causes

• CommonWater heater bypass valve left in bypass positionIf a bypass valve is set for winterizing, water skips the tank entirely, so it never heats even if functioning correctly.
• CommonWater heater tank not filled with water firstRunning some water heater elements dry can trip a safety switch or damage the element.
• CommonTripped high-limit safety switchA reset button (often red) trips if the water gets too hot or if the unit ran dry, and needs manual resetting.
• PossiblePropane supply issue or igniter failure (gas models)Low propane, a closed valve, or a failed igniter prevents the burner from lighting.

What to do

1. Check that the bypass valve (usually near the water heater, look for 3 valves in a triangle) is set to normal operation, not bypass.
2. Make sure the water heater tank is actually filled with water before running the pump or connecting to city water, then run a hot faucet until air stops sputtering.
3. Look for a high-limit reset switch (often a small red button) on the water heater and press it if it's popped out.
4. For propane models, confirm the propane tank has fuel, the valve is open, and other propane appliances work to rule out a supply issue.
5. For electric models, check that the unit is plugged into shore power or the generator is running, and check the breaker for the water heater circuit.
6. If everything checks out but it still won't heat, the heating element (electric) or igniter/thermocouple (propane) may need replacement.

Tools and parts

• Basic hand tools

When to call a pro

If you smell gas, or the pilot won't stay lit after a couple of tries, have an RV technician or propane service inspect it rather than continuing to try.

Safety