How long do home systems last?

Most home systems fail at an inconvenient moment: the water heater on a holiday weekend, the AC in a heat wave. Knowing typical lifespans lets you start saving and comparing options before that happens. The ranges below are typical for well-installed equipment; yours may last longer or shorter.

Typical lifespans at a glance

System	Typical lifespan	Main factors
Tank water heater (gas)	8 to 12 years	Water hardness, flushing, anode rod
Tank water heater (electric)	10 to 15 years	Water hardness, element condition
Tankless water heater	15 to 20+ years	Descaling, water quality
Gas furnace	15 to 20+ years	Filter changes, annual service
Central air conditioner	12 to 17 years	Climate, coil cleaning, installation quality
Heat pump	10 to 15 years	Runs year-round, so wears faster
Sump pump	7 to 10 years	How often it runs, debris in the pit
Smoke alarms	10 years	Replace the whole unit, not just batteries
Carbon monoxide alarms	5 to 10 years	Check the date on the back of the unit
Garbage disposal	8 to 15 years	Use habits, motor size

How to find the age of your equipment

Look for the data plate or rating label on the unit. Manufacturers often encode the manufacture date in the serial number, typically as the year and the week or month in the first few characters, but the format differs by brand. Searching the brand name plus "serial number date" usually turns up the decoding scheme. Alarms have a manufacture date printed on the back.

Signs a system is near the end

Water heater

• Rusty hot water or water around the base
• Loud rumbling that flushing doesn't fix
• Running out of hot water faster than before

Furnace

• Frequent repairs in the last two years
• Rooms heating unevenly, rising gas bills
• Yellow, flickering burner flames instead of steady blue (have a technician check promptly)

Air conditioner or heat pump

• Repeated refrigerant leaks
• Can't keep up on moderately hot days
• Loud compressor noises or frequent breaker trips

Repair or replace?

A rule of thumb many HVAC technicians use: multiply the age of the unit in years by the repair cost. If the result is over about $5,000, replacement is usually worth considering. It's only a starting point, but it captures the idea that a big repair on an old system often buys only a few more years.

Other things to weigh:

• Efficiency. A new system may cost noticeably less to run than one from 15 years ago.
• Rebates and tax credits. Utilities and governments often offer incentives for efficient equipment, especially heat pumps and heat pump water heaters. Check what currently applies in your area before buying.
• Refrigerant. Older air conditioners may use refrigerants that are being phased out, which can make repairs more expensive.
• Timing. Replacing on your own schedule, in spring or fall, gives you time to compare quotes instead of accepting the first one during an emergency.

How to get more years out of everything

• Change HVAC filters on schedule.
• Book annual service: heating in fall, cooling in spring.
• Flush tank water heaters yearly and check the anode rod every few years.
• Keep outdoor units clear of plants and debris.
• Test sump pumps every few months.

Our seasonal maintenance checklist puts all of this on a calendar.