Start with what kind of heater you have
Most houses in Golden Hills and the rest of Fullerton have a tank water heater in a garage, a closet or an outdoor enclosure. The label on the side tells you whether it burns natural gas or runs on electricity, its capacity, and a manufacture date coded into the serial number. Write those down before you do anything else, because every next step depends on them.
A gas tank heats water with a burner under the tank, controlled by a gas valve and lit by a pilot or an electronic igniter. An electric tank uses one or two heating elements and thermostats behind access panels. No hot water at all points to a different set of causes than lukewarm water or hot water that runs out quickly.
Safe checks before you call
None of these require tools or opening anything up. Follow the instructions printed on your heater's label.
- Gas heater: look through the sight window for a flame or a status light on the gas control. A blinking light often signals a fault code explained on the label.
- Gas heater: confirm other gas appliances such as the stove still work, which rules out a gas supply problem.
- Electric heater: check the breaker panel for a tripped double breaker labeled for the water heater. Reset it once only; if it trips again, leave it off.
- Check the temperature setting has not been turned down by accident.
- Look around the base and the pipes on top for water, rust streaks or scorch marks.
- Note whether the problem is no hot water, lukewarm water, or hot water that runs out fast.
Common causes by symptom
| What you notice | Gas tank: likely cause | Electric tank: likely cause |
|---|---|---|
| No hot water at all | Pilot out, failed thermocouple or flame sensor, faulty gas control valve | Tripped breaker, failed upper element or thermostat, tripped high-limit switch |
| Lukewarm water only | Thermostat setting, burner not firing fully, heavy sediment | Failed lower element, thermostat out of calibration |
| Hot water runs out fast | Sediment taking up tank volume, broken dip tube | Failed lower element, sediment, broken dip tube |
| Pilot will not stay lit | Thermocouple, flame sensor, draft or venting issue | Not applicable |
What a licensed plumber typically checks
- Confirm fuel and power.Gas supply to the heater's shutoff, voltage at the electric heater, and the condition of the flex connector or wiring.
- Test the ignition or heating parts.Pilot assembly, thermocouple or flame sensor and gas control on gas units; elements and thermostats on electric units.
- Check venting and combustion air.A gas heater needs a clear vent and enough air to burn properly. Poor draft can put the pilot out and is a safety concern.
- Inspect the tank itself.Corrosion, leaks at the tank body, and the age of the unit decide whether a part replacement makes sense.
Repair or replace?
There is no single age at which every tank should be replaced, but these patterns help.
Repair usually makes sense when
- The tank is dry and shows no rust at the seams
- A single replaceable part has failed, such as a thermocouple or element
- The heater is well within its warranty period on the label
- The seismic strapping and venting are already in good order
Replacement is worth pricing when
- Water is coming from the tank body rather than a fitting
- Several parts have failed or the gas control valve is gone on an older unit
- Heavy sediment and rusty hot water point to an interior near its end
- The heater is past its warranty and you want to change size or type
Questions to ask before approving work
- Which part failed, and can you show me how you tested it?
- Is this a repair on a tank that still has useful life, in your view?
- If I replace instead, what is included: strapping, venting, relief valve piping, haul-away and permit?
- Will you check the gas line and venting while you are here?
- What is your CSLB license number?
Common questions
Can I relight the pilot myself?
Many gas water heaters have relighting instructions on the label, and following them is a common homeowner task. If you smell gas, the pilot will not stay lit, or you are unsure, stop and call a licensed plumber or SoCalGas.
Why does my electric heater keep tripping the breaker?
A shorted element, damaged wiring or a failing breaker can all cause it. Repeated resets are not safe; leave the breaker off and have the heater diagnosed.
How do I read the age of my water heater?
Manufacturers usually encode the month and year in the serial number. The format varies by brand, so look up the brand's serial number guide or ask the plumber to read it for you.
General information for Golden Hills, not a quote or professional advice. In an emergency, call 911.