If the hot water used to last and now does not, something changed. If it never lasted, the heater may simply be too small.
Common causes
- Thermostat set too low.
- Sediment or lime taking up space and insulating the water from the heat source; San Diego's hard water speeds this up.
- A failed lower heating element or thermostat (electric).
- A cracked or broken dip tube letting cold water mix at the top of the tank.
- A heater too small for the household's demand.
- Leaking hot water faucets.
What you can check, and what needs a technician
Check the thermostat setting (120°F is the recommended setting) and flush the tank. A.O. Smith gives a technician test for the lower element: a temperature drop of more than 30°F after using 60% of the tank. Bradford White's manual says not to attempt repairs to thermostats, elements or wiring yourself.
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 residential electric water heater manual (185762); Bradford White, When you run out of hot water; A.O. Smith Technical Bulletin 36 (insufficient hot water); Bradford White installation & operating manual.
Water Heater Repair in San Diego →