Reading the Water Heater Label

Find it

The rating label is on the side of the tank, usually near the top or next to the gas control or electrical panel.

Serial number and age

Most makers code the manufacture date into the serial number. Search the brand name with "serial number date" to decode it. Many tanks last around eight to twelve years.

Capacity

The tank size is listed in gallons. In winter, incoming water is much colder, so a heater that's barely big enough in summer may fall short in January.

Fuel and power

Gas models list BTU input and gas type; electric models list voltage and element wattage. The plumber needs these to match parts or a replacement.

Look around the tank

While you're there, check for water on the floor, rust on fittings and scale or crust around the pipes on top.

Next step

Send the label details with your request. See water heater repair.

First-hour rating

Many labels also show a first-hour rating, how much hot water the heater can deliver in a busy hour. In a house where several people shower each morning, that number matters more than the tank size when choosing a replacement.

Expansion tank

Check whether there's a small expansion tank on the cold line near the heater. If there isn't one, ask whether your system needs it when the heater is serviced or replaced.

Photograph it

Take a clear photo of the label and keep it on your phone. It's the quickest way to answer a plumber's questions.

More plumbing guides

• Winterizing a Pocatello Home
• Service Lines and Deep Frost
• Finding the Water Shut-Off in a Basement or Crawl Space
• Is There a Leak? Check Your Meter
• Checking an Idaho Plumbing License