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Estimating the Life Span of a Water Heater

While the typical water heater has a life span of about 12 years, a variety of factors influence the life span. Beyond the basic telltale signs, such as a leaky puddle under the heater or cold showers in the morning that indicate that a new water heater is probably in order, consider these factors that pertain to its life span:

Hot Water Heater ComponentsCorrect Installation

  • A water heater should generally be installed upright. Installing a water heater on its side will place structural stress on it due to inadequate support for the heater and its pipes, and may cause premature failure.
  • Water heaters should be installed in well-ventilated areas for fire safety requirements, preventing nitrous-oxide buildup and because poor ventilation can shorten the lifespan.
  • A water heater should not be placed in an area susceptible to flood damage. Water can rust the exterior and pipes, decreasing the life expectancy and efficiency of the unit. A water heater is best placed in an easily accessible area for maintenance.
  • Was the water heater installed professionally? Homeowners may install their own units to save money, but the installation of a tankless gas water heater, for example, requires more skill than the average DIY task.


  • The greater the volume of water used, the greater the corrosive effect of the water will be and the harder the unit will work to heat the water.

Construction Quality

  • As with most household systems and components, you get what you pay for in a water heater. A good indication of a water heater’s construction quality is its warranty. Longer warranties naturally imply sounder construction.
  • Models with larger heating elements have a much better resistance to mineral buildup or scum.
  • Some models come with a self-cleaning feature that flushes the pipes of mineral deposits. Models with larger or thicker anodes are better-equipped to fight corrosion.

Maintenance and Parts Replacement

  • Where there is a higher mineral content (hardness) to the water, water heaters have shorter life spans.
  • Mineral buildup reduces the units’ efficiency. Periodically flush the water heater system, to remove some of the buildup.
  • It is important not to damage the water heater valve, which is usually made of plastic and is easy to break.

Repair or replace? A good rule is if the total repair cost per year is greater than 10% of the cost of buying and installing a new water heater, it is probably not worth replacing damaged parts.