Water heater (tankless) lifespan: 15–20 years

A water heater (tankless) typically lasts 15–20 years. The most common failure point is scale buildup on the heat exchanger; igniter failure. Typical manufacturer warranty: typically 10–15 years on the heat exchanger.

Typical lifespan

15–20 years

Common failure point

Scale buildup on the heat exchanger; igniter failure

Typical warranty

Typically 10–15 years on the heat exchanger

These are general published reference ranges, not a model-specific lookup; always verify against the manufacturer's own documentation. Age and model identity cannot establish safety. Record your own installation or manufacture date, inspection observations, and a replacement-cost range in the ApplianceAgeBook workspace to plan a specific reserve for your unit.

Method version 1.0.0. Publication date: 2026-09-11.