Start with the simple checks. Most no-hot-water calls come down to power, gas supply or a pilot that has gone out.
Safety first
If you smell gas, do not light anything or touch electrical switches. Leave the house and call SDG&E or 911 from outside. Electric heaters: never remove an access panel with the power on.
Electric water heater
- Make sure the heater's switch is on and the breaker has not tripped.
- If the breaker trips again or the high-temperature limit keeps opening, stop resetting and call a technician.
- Failed thermostats and heating elements are technician repairs.
Gas water heater
- Check whether the pilot is lit (most heaters have a sight glass).
- Make sure the gas supply valve and meter are on; check other gas appliances.
- If the pilot is out, follow the lighting instructions on the heater label. A.O. Smith says not to continue if you smell gas, and to wait at least 10 minutes after turning off the gas before relighting.
- Keep the area around the heater clear so the air intake is not blocked.
Tankless heaters
Check the display for an error code and look it up in the manual. See our error-code pages for Rinnai, Navien, Noritz and Rheem.
Common questions
How long does a water heater take to heat back up?
A.O. Smith gives about 30–40 minutes for gas and 60–90 minutes for electric tank heaters.
The pilot keeps going out. What now?
Repeated pilot outages point to causes like a failed thermocouple, gas supply or airflow problems, which are technician work. See our pilot light page.
General information, not professional or legal advice; follow your manufacturer's manual, and your installer and local permit office have the final word. Sources:A.O. Smith, Water heater not working; A.O. Smith residential electric water heater manual (185762); A.O. Smith, How to light a pilot light.
Water Heater Repair in San Diego →