• Capacity: 60 gal.
  • Power: 4500W
  • Voltage: 240V
  • Warranty: 6 years
  • 2
    This question can't be answered; you need to look at statistics from that model, or at least that manufacturer. Odds are, if it's got a 6 year warranty, they assume the odds are that it won't fail in those first 6 years. (so 6 years = MTBF - (factor), where (factor) might be 1 to 3 standard deviations, depending on how risk adverse they are)
    – Joe
    Feb 2, 2011 at 18:58
  • @Joe, Thanks. I have an inkling that this might be useful for others. Maybe. So if you post that as an answer, I'll accept it.
    – MPelletier
    Feb 2, 2011 at 23:15

1 Answer 1


I have never heard the term "mean time between failure" used for water heaters. Love it. I can tell you, that on my inspection reports, I advise that the average expected life span of an electric water heater is 10 to 15 years. If you have very hard water, don't drain it annually to remove sludge, or check/replace the sacrificial rods every 3 yrs, you may not see the maximum life capability. I have seen them last up to 20 years, but that is rare.

  • The MTBF thing is really just professional deformation (developer).
    – MPelletier
    Feb 3, 2011 at 0:48
  • We used that term all the time back when I was an engineer for Motorola. Always thought of it as an electronic term. But I still love it!!! lol Feb 3, 2011 at 0:54
  • And thanks for the tips. I don't know if it was done often before, but I've had the house for a year, so I'm due!
    – MPelletier
    Feb 3, 2011 at 0:56

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.