The service life of a residential Bock water heater greatly depends on the supply of water. In areas with untreated “hard water” standard glass-lined oil-fired water heater tank may only last 6-7 years. On the other hand, in areas with naturally clean water, we have seen Bock water heaters lasting 25 years. (Get a sediment filter installed on the Cold side of your water heater if you live in an area with Hard Water.) On average Bock water heater tanks last 12-16 years in our area of operation, New Haven Connecticut.
Well water always has different types of minerals naturally within the water, and some areas have a higher mineral content than others. The geographic location around Ridgefield CT has notoriously hard water, and well water in Shelton CT is free from hard water problems for the most part. Note: City or town provided water usually does not have issues with hard water since it passes through a water treatment facility on before arriving at your home.
Why minerals/ “hard water” is problematic for water heaters. Minerals within the “hard water” eagerly want to break down the water heaters’ inner steel tank, (water eats steel for breakfast) and your basic steel water heater is modestly equipped to defends itself from hard water with two levels of protection. The first is a Glass-Lining, and the second is a self-sacrificing Anode Rod. The glass lining is exactly what is sounds like, the inner steel tank is sprayed with liquid glass and it bonds to the steel walls. Anode Rods provide another layer of protection but by design, they get eaten up by the minerals, instead of the water heater.
**IF you have normal city provided water (not well water) and your Bock water heater started leaking before 10 years of it’s original installation, the water heater was most likely handled roughly on it’s way to your home. Though these tanks are heavy, however the glass-lining makes them are very fragile. If they are dropped on bagged around, the inner glass-lined can get cracked and if so, water starts to eat the water heater’s steel tank much faster than normal, the tank then fails prematurely. When this happens the water heater usually fails in the 5-7 year range.