Water Heater Guide for Inland Empire Homeowners

Straight answers to the questions we get most, from reading your water heater's age to what it costs to run. If you'd rather we just take a look, text us a photo of the label.

How old is my water heater?

The serial number on the rating plate (the label on the side of the tank) contains the manufacture date. Here's how to read the most common brands.

A.O. Smith and State

On units made since about 2008, the first two digits are the year and the next two are the week. Example: serial 1836111786352 was built in week 36 of 2018. Older serials start with letters; text us a photo and we'll decode it.

Bradford White

The first letter is the year and the second letter is the month. Bradford White repeats its year letters every 20 years, so use the install date or condition to pick the right decade.

Month letters: A = Jan, B = Feb, C = Mar, D = Apr, E = May, F = Jun, G = Jul, H = Aug, J = Sep, K = Oct, L = Nov, M = Dec. Example: serial KH1234567 = August 2013.

Other brands

Rheem, Ruud, American and others each use their own format. Text us a clear photo of the label and we'll tell you the age and whether it's still under warranty.

Not sure if yours is still covered? Use our warranty check and we’ll look it up for you.

Repair or replace?

Replace it if the tank itself is leaking or the unit is more than 10–12 years old. Repair it if it's younger and the problem is a part such as a thermostat, igniter, gas valve or heating element. Hard water and hot garages shorten tank life here, so many tanks fail sooner than the national average.

When replacing makes sense, here’s what goes into tank water heater replacement.

What size water heater do I need?

These are starting points. We size by how your household actually uses hot water and the unit's first-hour rating.

Thinking about a different type? Compare tankless water heaters and heat pump water heaters.

Emergency shut-off

If your water heater is leaking or acting dangerously, shut it down first, then text or call us.

1. Gas water heaterTurn the gas valve on the water heater to OFF, then close the cold-water valve on the pipe above the tank.
2. Electric water heaterSwitch off the water heater’s breaker in your electrical panel, then close the cold-water valve above the tank.
3. If you smell gasLeave the house, don’t touch light switches, and call SoCalGas at 1-800-427-2200 or 911 from outside.

Warm spot on the floor, or a water heater that never stops running? That can be a leak in a hot water line under the slab. See hot water slab leaks.

How to flush a tank water heater

Flushing once a year removes the hard-water sediment that shortens tank life. If the drain valve is old or stuck, stop and call us; forcing it can cause a leak.

1. Turn the gas valve to OFF or switch off the breaker.
2. Let the water cool for a few hours. Tank water is hot enough to scald.
3. Attach a garden hose to the drain valve near the bottom and run it outside or to a floor drain.
4. Close the cold-water valve, open a hot-water faucet in the house, then open the drain valve.
5. Let it drain, then briefly open and close the cold-water valve to stir up remaining sediment until the water runs clear.
6. Close the drain valve, open the cold-water valve, and let the tank fill until water flows steadily from the hot faucet.
7. Turn the gas or power back on.

Dripping relief valve? See expansion tanks and relief valves.

Brown or rusty water when you flush? Read what rusty water from the tap means.

What temperature should my water heater be set to?

120°F is the right setting for most homes. It's hot enough for showers and dishes, saves energy, and greatly lowers the risk of scalding, especially for children and older adults. Each 10-degree reduction trims water heating energy by roughly 3–5%.

More on scald safety and the right temperature.

Running a restaurant, school or hotel? See commercial water heaters for storage temperatures and mixing valves.

What does it cost to run a water heater in Southern California?

At 2026 utility rates (Edison about 34.5¢ per kWh, SoCalGas about $2.10 per therm), a typical family using 64 gallons of hot water a day pays roughly:

Estimates assume 64 gallons a day heated 67°F and typical efficiency ratings (gas tank UEF 0.62, gas tankless 0.93, electric tank 0.93, heat pump 3.5). Your cost depends on household size, thermostat setting and your Edison rate plan.

See our side-by-side: which type of water heater saves the most money.

Rebates and the gas water heater rules

Can I still replace a gas water heater with a new gas one? Yes. In June 2025 the South Coast AQMD board voted 7–5 against proposed rules that would have phased out gas water heaters at replacement time, so gas-to-gas replacement is still allowed. New gas units must meet the district's low-NOx standards.

Are there rebates? Most statewide rebates for heat pump water heaters, including TECH Clean California, were fully reserved by late 2025 and aren’t taking new applications. Utility and local offers come and go, so we check what’s available for your address when we quote. The federal 30% tax credit for heat pump water heaters (25C) ended for installations after December 31, 2025.

What is FVIR? Every 30-, 40- and 50-gallon atmospheric gas water heater sold in the U.S. since 2003–2005 is built to the Flammable Vapor Ignition Resistant (FVIR) standard, which helps keep gasoline or paint-thinner vapors in a garage from igniting at the burner. If your gas water heater predates FVIR, it's old enough that replacement is usually the smarter choice.