How long does a water heater last?
Quick answer
A conventional tank water heater typically lasts 8–12 years for gas and 10–15 years for electric. Tankless units often last 18–20 years. Hard water, skipped flushing, and a spent anode rod shorten that — and a tank past its expected age that's rusting or leaking is on borrowed time.
Common causes
- Type and fuel: gas tank (8–12 yrs), electric tank (10–15), tankless (18–20).
- Water hardness — mineral sediment accelerates corrosion and overheating.
- A used-up sacrificial anode rod, which then lets the tank itself corrode.
- Skipped annual flushing, letting sediment build up at the bottom.
What to check first
- Read the install date or decode the serial number to find the unit's age.
- Look for rust-colored hot water, rumbling/popping sounds, or moisture at the base.
- Check whether it still heats a full, consistent tank or runs out faster than it used to.
- Note when it was last flushed and whether the anode rod has ever been replaced.
When it's urgent
Active leaking from the tank body, no hot water with visible corrosion, or (for gas) any gas smell is urgent. A failing tank can flood the area suddenly, so a unit that's both past its expected age and showing rust should be replaced proactively, not after it bursts.
DIY vs. call a pro
You can likely DIY
- Finding the age, flushing sediment, and setting a maintenance reminder.
- Checking and replacing the anode rod (extends tank life significantly).
- Insulating exposed hot-water lines for efficiency.
Call a pro for
- Full replacement, especially gas units (gas + venting) and code upgrades.
- Diagnosing recurring sediment, pressure, or relief-valve problems.
- Sizing and installing a tankless upgrade.
Estimated cost range
How HouseCue helps
HouseCue is a private, homeowner-first app that turns this from a one-time worry into a tracked plan. Snap a photo for an AI diagnosis, upload your inspection report to auto-build a handbook, and get seasonal reminders for your roof, HVAC, water heater, plumbing, and electrical — so nothing slips. Connecting with a pro is always optional and only when you choose.
Get started freeFrequently asked questions
Can I extend the life of my water heater?
Yes — flush the tank annually to clear sediment, replace the anode rod when it's used up (often every few years), and keep the temperature around 120°F. These cheap habits can add years to a tank's life.
What are the signs a water heater is going bad?
Rusty hot water, rumbling or popping noises, water pooling at the base, inconsistent heating, and simply being past its expected age. Several of these together mean it's time to plan a replacement.
Is a tankless water heater worth it?
Tankless units last longer (often 18–20 years), save space, and only heat water on demand, but cost more up front and may need gas/venting upgrades. Whether the long-term savings pencil out depends on your usage and energy rates.
Related guides
HouseCue guides are general educational information, not professional inspection, engineering, or contracting advice. Costs vary by market. For safety issues — gas, electrical, structural, or major water — contact a qualified professional.