Tankless water heaters have become a popular choice for Bay Area homeowners, and it’s easy to see why! Tankless models take up less space and use less energy than their tanked counterparts—plus, they deliver reliable hot water on demand. That means no more cold shower surprises or waiting for the water to warm up again.
But how long will that efficiency last? Like any essential home system, a tankless water heater has a lifespan. Understanding their expected longevity—and what to watch for as they age—can help keep your hot water flowing smoothly for years. In this post, we’ll cover the typical lifespan of a tankless water heater, what to expect from a well-maintained system, and the warning signs to look out for as it ages.
Tankless Water Heater Lifespan
When investing in a new water heater, it’s natural to want to know how long it will last. The lifespan of your tankless water heater depends on 4 key factors: water quality, maintenance routine, use and demand, and installation quality.
1. Hard Water and Tankless Water Heaters
Water quality is one of the biggest factors that affects how long your water heater lasts—whether you have a traditional tanked model or a tankless system. Hard water contains high levels of minerals (such as calcium and magnesium), which can cause problems inside any water heater.
Tanked water heaters have an anode rod that attracts these corrosive minerals, helping prevent rust and extend the life of the tank. But over time—or in areas with hard water—the anode rod wears out, leaving the tank vulnerable to corrosion. Meanwhile, minerals can settle at the bottom, creating sediment buildup that reduces efficiency and damages the system.
Tankless water heaters don’t have a tank or an anode rod, but they aren’t immune to corrosion or mineral buildup. Hard water minerals can form a crusty layer, known as “scale,” inside the tankless unit. This scale can coat the heating elements and restrict water flow. When that happens, your tankless system works harder and consumes more energy to compensate—which can lead to faster wear and higher utility bills.
To protect your tankless water heater and keep it running smoothly, consider a water treatment plan. Water softening systems, such as ion exchange or salt-based softeners, are effective ways to prevent mineral buildup and prolong the life of your heater. Most warranties for tankless systems require a water softener.
2. Maintenance and Regular Service
Keeping to a regular maintenance schedule can help your tankless water heater last longer and work more efficiently. Most manufacturers recommend a professional tune-up once a year—but if your home has hard water, more frequent service (every 6–9 months) may be needed to manage mineral buildup. A water heater tune-up includes flushing your water heater and inspecting it for any issues that need attention.
Routine maintenance may feel like just another task on your to-do list, but it pays off. Tune-ups help keep your system clean, catch small issues early, and prevent bigger problems down the road.
3. Daily Demand and Usage Patterns
Tankless water heaters are built for frequent use, but high demand can still add wear over time, especially if the system isn’t the right size for your household. Running multiple hot water fixtures simultaneously or taking several long showers consecutively can put extra strain on the unit.
Occasionally taking a long shower isn’t a problem, but if hot water use is heavy day after day, it’s important to make sure your water heater is the right size to keep up. Using water-efficient fixtures and spacing out hot water use when possible can help ease the load on your system.
4. How Proper Installation Protects Your Tankless System
Proper installation can significantly impact the longevity of your tankless system. A poorly installed unit may face issues early or wear out faster. Always work with a professional plumber who has experience with tankless systems, and schedule routine service to help your system perform reliably from the start.
Tanked Vs. Tankless: Do Tankless Water Heaters Last Longer?
Understanding how water quality affects your system can help explain the difference in lifespan between tanked and tankless water heaters.
How Long Do Tankless Water Heaters Last?
With regular maintenance, tankless water heaters often last 15 to 20 years or more.
In comparison, tanked water heaters typically last around 8 to 12 years, depending on usage, water quality, and upkeep. Since tankless systems don’t store water or rely on an anode rod, they avoid many of the corrosion and buildup issues that shorten the life of tank-style units—giving them an edge in long-term performance.
For more information on the energy efficiency of tankless water heaters, check out “Tankless or Demand-Type Water Heaters” from Energy.gov.
How To Help Your Tankless Water Heater Last Longer
- Stay on top of routine maintenance and service appointments.
- Keep an eye out for any red flags that could indicate an issue, such as a lack of warm water from your faucets or water that takes a long time to heat up.
- If you suspect an issue with your tankless water heater, contact a professional plumber in your area.
When Is It Time to Replace Your Tankless Water Heater?
Consider replacing your unit if you notice:
- Visible wear and tear to your unit
- Sudden performance issues (such as no hot water or slow heating)
- Your water heater is older and showing signs of age
Ready to Upgrade?
Switching to a tankless water heater means enjoying endless hot water and better energy use. With proper care, attention to water quality, and professional support, your new system will deliver dependable comfort well into the future.
Professional Tankless Water Heater Installation and Service in the Bay Area
Need help with a tankless water heater installation, maintenance, or replacement? Wizard Plumbing and Drain offers expert service and reliable results. Our team is ready to provide quality care that keeps your system running efficiently for years to come.
Contact Wizard Plumbing and Drain today or give us a call at (650) 514-5401. We are proud to serve our local community in San Mateo, California, and the surrounding areas.
