What the label tells you
Every tank and tankless water heater carries a rating label, usually a sticker or metal plate on the side of the tank or on the front of a tankless unit. It lists the manufacturer, model and serial number, the fuel and input rating, the capacity, the voltage for electric units and often the first-hour rating or flow rate. The serial number usually encodes the date of manufacture.
Plumbers use these details to judge age, find parts and tell whether a replacement can go in the same spot. Writing them down also helps if the label later fades, peels or gets hidden behind a new strap.
Fill-in label record
| Item | Where on the label | My heater |
|---|---|---|
| Manufacturer | Top of the label or logo on the jacket | |
| Model number | Marked Model or M/N | |
| Serial number | Marked Serial or S/N | |
| Manufacture date | Decoded from the serial number, or printed | |
| Fuel | Natural gas, propane or electric | |
| Capacity | Gallons for tanks | |
| Input rating | BTU per hour for gas, watts for electric | |
| Voltage | Electric and heat pump units | |
| First-hour rating or GPM | Energy label or rating plate | |
| Installed by and date | Your paperwork or permit record |
Getting a clear copy
- Turn on a light.Labels in garages and closets are often in shadow. A flashlight held at an angle cuts glare.
- Take a photo first.Photograph the whole label, then close-ups of the model and serial number.
- Copy the details.Write them into the table above, double-checking letters and numbers that look alike.
- Decode the date.Use the manufacturer's serial number guide, or ask a plumber to read it.
- Store it.Keep the record with your home papers and the photo on your phone.
Why each detail matters
- Age
- Helps decide between repair and replacement
- Fuel and input
- Determines gas line, venting and electrical needs
- Capacity and rating
- Shows whether the heater suits the household
- Model
- Lets a plumber check parts and the installation manual
Common questions
Where is the label on a tankless water heater?
Usually on the front cover or the side of the unit. Some models also show details on the display or inside the front panel; do not open panels on gas units yourself.
How do I find the age of my water heater?
Most manufacturers code the month and year in the serial number. The code differs by brand, so check the maker's guide or ask a plumber.
Do I need this if I am calling about a leak?
It is helpful but not urgent. Stop the water first, then take a photo of the label when it is safe.
General information for Brea, not a quote or professional advice. In an emergency, call 911.