How to Fix a Water Heater That's Not Working

Most water heater problems stem from faulty pilot lights, tripped breakers, or sediment buildup. Start with basic checks like power and gas supply before moving to component replacement.

1. Verify Power Reaches the Unit. For electric units, verify the circuit breaker hasn't tripped and flip it off then back on. For gas units, ensure the gas valve is fully open and you can smell gas at the unit. Look for any loose electrical connections at the unit itself.
2. Check the Pilot Flame. On gas water heaters, remove the access panel and look for a blue flame. If it's out, follow the lighting instructions on the unit's label. Hold the pilot button down for 60 seconds after lighting to ensure the thermocouple heats up properly.
3. Confirm Temperature Settings. Set the temperature dial to 120°F and wait 30 minutes. For electric units, press the reset button on the upper thermostat if there is one. Check that both upper and lower thermostats are set to the same temperature.
4. Test Elements With Multimeter. Turn off power and remove the access panels. Use a multimeter to test continuity across the heating element terminals. A reading of 10-16 ohms indicates a working element. Replace any elements showing infinite resistance or zero resistance.
5. Drain Tank Completely. Turn off the power and water supply, then connect a garden hose to the drain valve. Open the valve and let the tank drain completely. Turn the water back on briefly to stir up remaining sediment, then drain again until water runs clear.
6. Swap the Thermocouple. If the pilot won't stay lit, unscrew the thermocouple from both the pilot assembly and gas control valve. Install the new thermocouple in the same position, ensuring the tip sits in the pilot flame when lit.