How Long Should a Water Heater Really Last?

So, how long should a water heater really last? The honest answer is that it varies by type of unit, water quality, installation quality, and how much routine maintenance it gets. Still, there are realistic lifespan ranges that most homeowners can use as a benchmark.

For many households, the deciding factor is whether the system is a conventional storage tank or a tankless (on-demand) heater. In general, tank models are replaced sooner, while tankless units tend to offer longer service life—assuming they’re installed correctly and maintained over time.