How old is your water heater?

Type the serial number from the label on the tank. You'll see the month it was made, its age, and whether it's time to plan a replacement.

Also works for furnaces and AC units. 32 brands in all.

Rating label on a water heater with serial number 1210A002243 highlighted
This is the serial numberMade March 2012A.O. Smith: "12" is the year, "10" is the week

Pick your brand

The brand name is on the front of the unit or at the top of the label.

A.O. SmithBradford WhiteRheemStateNavienRinnai

All 14 water heater brands

Where's the label?

Look for a silver or white sticker with "Serial No." or "S/N". Take a photo of the whole label; 0 and O are easy to mix up.

Water heater with the rating label location marked

Water heater

On the side of the tank, just above the gas valve or the upper panel.

Furnace with the rating label location marked

Furnace

Inside the cabinet. Take off the lower front panel to see it.

Air conditioner with the rating label location marked

Air conditioner

On the outdoor unit, on the side panel next to the pipes.