The Atwood water heater is a common component in RVs, delivering hot water for showers, dishes, and cleaning. When it fails on either gas or electric mode, it disrupts comfort and routines. This guide walks through practical, safety‑focused troubleshooting steps for Atwood water heaters not functioning on gas or electric, with emphasis on identifying whether the issue is electrical, mechanical, or fuel‑supply related. Readers will gain actionable checks, what to test, and when to call a professional.

Initial Safety Checks And Quick Wins

Before diving into complex diagnostics, perform quick safety and reliability checks to rule out simple causes. First, ensure the RV battery is charged and the onboard generator or shore power is connected as required for electric operation. Check the water heater switch located inside the RV and the exterior access panel for any obvious signs of damage or loose wiring. For gas operation, confirm the propane supply is open and the exterior regulator is delivering gas. A clogged vent or blocked exhaust can also cause a burner to fail to ignite.

Gas Mode Not Igniting Or Running

Gas operation relies on a propane supply, a functioning igniter, and proper ventilation. If the Atwood heater won’t ignite or stay lit in gas mode, consider these steps:

Propane Supply And Regulator: Verify at least one full cylinder or a connected gas line with adequate pressure. Listen for a hiss when opening the valve. If the supply is low or the regulator is failing, the burner may not ignite.
Gas Valve And Burner: Inspect the gas valve to ensure it is fully open. Check the burner for signs of dirt, corrosion, or debris that could block gas flow. A clogged burner can prevent ignition or cause flame instability.
Igniter Function: The Atwood unit uses an electric spark to ignite gas. If you hear clicking but no flame, the igniter tip may be dirty or misaligned. Clean the electrode cautiously and verify proper gap with the burner housing guidelines.
Vent And Exhaust: A blocked vent can force the burner to shut down as a safety measure. Inspect the vent cap and chimney for obstructions such as lint, insect nests, or soot buildup.
Thermal Cutoffs And Safety Switches: The water heater has a high‑limit switch and temperature sensor. If the switch is tripped or the sensor reads incorrect temperatures, ignition can be inhibited. Reset or test per manufacturer instructions, ensuring there is no water leakage that skews readings.

Electrical Operation Not Heating On Electric Mode

When the water heater fails to heat using electric power, the issue typically involves power delivery, internal components, or the thermostat. Consider the following checks:

Power Source: Confirm the RV is plugged into shore power or the generator is running. Check the circuit breaker or fused disconnect that serves the water heater. A tripped breaker or blown fuse will silence electric heating.
Thermostat Settings: Verify the thermostat is set to the desired water temperature. Some units have multiple settings or a 120V/240V switch; incorrect configuration can prevent heating.
Heating Element: Atwood electric models rely on one or two heating elements. A failed element reduces or eliminates heating. Visual inspection is not possible in most models; a continuity test with a multimeter or a professional diagnostic is required.
Control Board And Wiring: Loose or corroded connections at the control board, high‑limit switch, or terminal blocks can interrupt power flow. Inspect accessible wiring for signs of wear, scorching, or loose terminals. Do not attempt repairs if uncomfortable; electrical work can be hazardous.

Water Temperature Sensitivity And Sensor Issues

Inconsistent or low water temperatures can be traced to sensor or thermostat problems rather than the heater core itself. Consider these causes:

Temperature Sensor: Faulty sensors can misread water temperature, causing the heater to cycle on and off or not heat at all. A periodic calibration or sensor replacement may be required.
Thermostat Calibration: If the thermostat is not calibrated correctly, it can prevent the heater from reaching set temperatures. Recalibration or replacement might be necessary per manufacturer guidelines.
Water Flow Rate: Extremely low incoming water pressure or blocked filters can hinder heating performance. Ensure adequate flow and check for mineral buildup in the lines or in the tank.

Common Internal Causes And Diagnostic Path

When basic checks fail to locate the issue, a more detailed diagnostic path can help isolate trouble areas:

Diagnostic Codes: Some Atwood models display error codes via LEDs or internal displays. Refer to the manual to interpret codes and apply recommended actions.
Continuity And Voltage Tests: Use a multimeter to check for continuity across heating elements, fuses, and control components. Verify proper voltage supply to each element and the control board.
Water Heater Bypass: Ensure the unit is not in bypass mode, which would prevent heating even when powered. Check plumbing valves and bypass connections if present.
Ignition Modules And Gas Assemblies: For gas operation, a faulty ignition module or damaged gas burner assembly can prevent ignition. Replacements should be performed by a qualified technician.

Maintenance And Prevention Tips

Regular maintenance helps prevent many common failures and extends the life of the Atwood water heater. Implement these practices:

Annual Inspection: Schedule a yearly inspection of propane connections, venting, and electrical connections. Have a professional service the unit to check seals and gas pressure.
Vent Cleaning: Clear vent paths of dust, debris, and bushings to ensure proper exhaust flow for gas operation.
Descale And Flushing: Periodically flush the tank to remove mineral buildup, especially in areas with hard water. Follow the manufacturer’s flushing procedure for your model.
Electrical Hygiene: Keep access panels closed and dry. Inspect wiring for wear or corrosion and replace damaged wiring promptly to prevent short circuits.

When To Seek Professional Help

Some issues require specialized tools and safety protocols. Seek professional assistance if any of the following apply:

Gas Safety Concerns: Suspected gas leaks, improper regulator performance, or persistent ignition failures. A licensed technician should handle gas components.
Electrical Diagnostics: Persistent heating failure with possible control board faults, fuse/ breaker problems, or unknown error codes.
Internal Component Replacement: Heating element replacement, sensor recalibration, or thermostat issues beyond basic troubleshooting.

Tips For Troubleshooting Logs And Documentation

Keeping records helps diagnose future problems and informs technicians. Useful notes include the date of failure, observed symptoms, propane status, power source, and any recent maintenance. Photograph access panels, wiring connections, and error codes when possible. This information accelerates diagnosis and repair.

Conclusion Of Key Steps

For an Atwood water heater not working on gas or electric, start with safety checks, verify power and fuel supplies, and inspect ignition components and vents. If basic checks fail, proceed to electrical diagnostics or gas burner assessment, and don’t hesitate to involve a professional for complex internal issues. Addressing issues promptly protects equipment and ensures reliable hot water in an RV setting.