How old is this?Snap the label on a water heater, furnace or AC: its age, its typical life, and what a new one costs
Your phone reads the label. Nothing is uploaded. Or type the brand and serial.
Snap the label on each system· A Northern Virginia basement
Life spans: DOE, NAHB, ENERGY STAR; costs: HomeAdvisor and Angi, October 31, 2026. Pictures: artist’s renderings.
The checker
Snap it or type it.
Getting the reader ready…
or type it
No serial? Pick the year it was made
Tip: fill the photo with the label, in good light, no glare. On an iPhone you can also press and hold the serial in your photo, tap Copy, and paste it here.
Pick what it is, then snap the label or type the brand and serial. You get the month and year it was made, how long it typically lasts, and what a new one costs.
Updated October 31, 2026Reads 40 brandsA 1-minute check, plus a 3-minute read
Quick answer
The month and year a water heater, furnace or AC was made are on its label: printed as a date (“MFG date”) or hidden in the serial number. Snap the label above and your phone reads it, or pick the brand and type the serial. A tank water heater typically lasts 10 to 15 years, a furnace 15 to 20, a central AC 10 to 15 and a heat pump about 16.1,2 A new tank water heater runs about $922 to $2,028, one-time, installed in Fairfax.4
Home systems, in six numbers
2026
Typical life in years from when it was made; costs one-time, installed.
Find the label
Where the label is.
Every water heater, furnace and outdoor unit has one. The red dot shows where to look.
Water heater
A white or silver sticker on the side of the tank, often above the gas valve or the lower panel. Tankless: on the side or under the front cover.
Furnace
Often on the outside of the cabinet; many sit inside the lower door, by the blower. Turn the furnace off at its switch before you open a door, or ask at the next service visit.
AC or heat pump (outside)
On the side of the outdoor unit, usually by the electrical box where the pipes and wires go in. The indoor coil has its own label.
Look for the words Serial, Ser. No. or S/N, and for a date beside MFG, MFD or Date of manufacture. The model number is a different line: it tells the size, not the age.
How long they last
Typical life, side by side.
From when it was made, in years.
In shortWater heaters and ACs go first, at 10 to 15 years; furnaces last longest.
Years from when it was made. Life is an average: a tank in hard water that is never flushed, or an AC that runs hard every summer, can go sooner; a well-kept furnace can go longer.1,2,3
What a new one costs
Replacing it, installed.
The typical range people paid, one-time, from HomeAdvisor and Angi.
| What | Typical range, installed | Where from |
|---|---|---|
| Tank water heater | $922 to $2,028one-time | Fairfax, VA4 |
| Tankless water heater | $1,200 to $3,500one-time | U.S. average5 |
| Furnace | $2,826 to $6,847one-time | U.S. average6 |
| Air conditioner | $4,268 to $7,753one-time | Fairfax, VA7 |
| Heat pump | $4,247 to $7,933one-time | U.S. average8 |
Installed prices reported to HomeAdvisor and Angi; Fairfax where they publish it, the U.S. elsewhere. A bigger home, a switch from gas to electric, new ductwork or a hard-to-reach basement costs more. Get two written quotes. Costs are one-time; the set-aside in the checker is per month.
Brands it reads
How each brand hides the date.
Forty brands, eleven codes. The highlighted part is the date.
| Brands | A serial like | Reads as |
|---|---|---|
| Rheem, Ruud, Richmond (water heaters) | 0618D01234 | Month, then year: June 20189,10 |
| A.O. Smith, State, Reliance, American, Whirlpool | 1215A001234 | Year, then week: week 15 of 2012 (since about 2008)11,10 |
| Bradford White | PC1234567 | Letters: P = 2017 (or 1997), C = March10 |
| Carrier, Bryant, Payne, Day & Night | 2215E12345 | Week, then year: week 22 of 201511,13 |
| Trane, American Standard | 180313596L | Year, then week: week 3 of 2018 (a letter first = 2001 or earlier)11,13 |
| Lennox, Armstrong, Ducane, AirEase, Concord | 5814E12345 | Plant, then year and month letter: May 201411,13 |
| Goodman, Amana, Janitrol | 1604123456 | Year, then month: April 201613 |
| Heil, Tempstar, Comfortmaker, Arcoaire, KeepRite | E171234567 | After the letter, year then week: week 12 of 201713 |
| York, Coleman, Luxaire, Guardian | W1F9123456 | 2nd and 4th = year, 3rd = month: June 201912 |
| Rheem, Ruud (heating and cooling) | W421724596 | After the letter, week then year: week 42 of 201713 |
| Frigidaire, Maytag, Westinghouse, Intertherm, Gibson, Tappan, Broan | GSD060700023 | 4th and 5th characters = year: 200613 |
Example serials are made up to show the pattern. Not listed (Rinnai, Navien, Mitsubishi, Fujitsu and others): look for the date printed on the label, or call the maker with the serial number.
Buying or selling
Why the age matters.
It is one of the first things an inspector writes down.
Buying
At a showing, snap the water heater, the furnace and the outdoor unit. A 14-year-old AC is not a reason to walk away, but it is a number to know before you write the offer and before the inspection.
Selling
An older system that works does not need replacing before you list; buyers and their inspectors will ask its age, so know it first.
Questions
What people ask about the age of a home’s systems.
How do I find out how old my water heater is?
Look at the label on the side of the tank. Some print the date (MFG date). Otherwise the serial number holds it: Rheem writes month then year (0618 = June 2018), A.O. Smith year then week (1215 = 2012, week 15), Bradford White two letters (PC = March 2017). Snap the label on this page and your phone reads it.
How long does a water heater last?
A tank water heater lasts 10 to 15 years, says the U.S. Department of Energy; a tankless one about 20 years.
How long does a furnace last?
15 to 20 years on average (18 for a gas furnace in the National Association of Home Builders study). ENERGY STAR suggests considering a new one past 15 years.
How long does an AC or heat pump last?
A central air conditioner 10 to 15 years, a heat pump about 16. ENERGY STAR suggests considering a new one past 10 years.
How much does a new water heater cost in Northern Virginia?
About $922 to $2,028, one-time, installed, in Fairfax (HomeAdvisor's typical range; average $1,423). Tankless: about $1,200 to $3,500 one-time.
How much does a new furnace or AC cost?
A furnace about $2,826 to $6,847 one-time, installed (U.S. typical range); a central AC about $4,268 to $7,753 one-time in Fairfax; a heat pump about $4,247 to $7,933 one-time (U.S.).
Does my photo get uploaded?
No. Your phone reads the label itself; the photo is not sent or saved. The reader downloads once, about 7 MB, the first time you snap a label.
Your next step
Looking at a house with older systems?
Send me the address or your photos of the labels. I will tell you what the ages mean for your offer or your sale, with real numbers, in English or Arabic.
اقرأ دليل شمال فرجينيا بالعربية ←
وكيلك العقاري الموثوق في شمال فرجينيا.
Keep exploring
Your next pages.
What to fix before selling
What pays back, and what to leave.
GuideMaking an offer
Inspection, appraisal and the rest, in order.
ToolHouse quick facts
Year built, size and lot for any address.
GuideHardware stores and home fixes
The nearest store, and what to do first.
ToolStreet noise meter
Another phone tool: how loud it is where you stand.
Keep reading
- CheckWhat to fix before sellingTap what your house has: see what to fix, what to make shine and what to skip. Staging, pre-listing inspections and selling as is.
- ToolMaking an offerHow homes like the one you want sold against asking, in dollars; then escalation, deposit, inspection and appraisal, in plain words.
- ToolHardware stores near youType an address: hardware stores within 3 to 5 miles, then the first 2 weeks in a new home by the year it was built, and DIY vs. a pro.
- ToolJust saw a house? Quick factsType the address of a house you just saw: size, value range, community sales, schools, noise, flood zone and sun on one screen.