The U.S. Department of Energy says most storage tank water heaters last 10 to 15 years. Some manufacturers plan for replacement closer to year 10, so age and condition both matter.
The Department of Energy's Energy Saver guide says most storage water heaters last 10 to 15 years, while tankless units can last more than 20 years.
Rheem, a water heater manufacturer, puts the figure lower. It says most conventional tank heaters last about 10 years and suggests planning for a replacement around that age.
The two numbers are not far apart. A practical reading is that a tank in its tenth year deserves attention, and one past 15 years is living on borrowed time.
Rheem lists five common warning signs. Some are maintenance problems. Others mean the tank is near the end of its life.
Hardness comes from dissolved calcium and magnesium. The U.S. Geological Survey says that when hard water is heated, calcium carbonate can form scale. That scale can shorten equipment life, raise heating costs and reduce the efficiency of electric water heaters.
The City of Fresno's 2025 Annual Water Quality Report lists total hardness at an average of 129 mg/L, with a range of 87 to 150 mg/L. On the USGS scale, 121 to 180 mg/L counts as hard.
Other nearby systems differ. The City of Clovis 2025 report lists an average of 117.7 ppm for its groundwater wells, and the City of Sanger 2025 report lists an average of 94.9 ppm. Your own number depends on which system serves your home, so check your utility's current report.
Flushing removes sediment from the bottom of the tank. Rheem recommends flushing once a year, and every 6 months if you have hard water. The Department of Energy guide suggests draining a quart of water from the tank every 3 months to remove sediment.
The basic steps are to shut off the power or gas and the cold water supply, run a hose from the drain valve to a safe spot, drain the tank, then refill it and restore power or gas. Hot water can scald, so let the tank cool and point the hose away from people and pets.
Rheem warns that flushing an older tank with hardened sediment yourself can lead to leaks or further damage. If the tank is old and has never been flushed, it is safer to have a professional look first.
A failed part on a younger heater is often worth repairing. A leak from the tank body, or a heater past 10 to 15 years with rust or repeated problems, is usually a replacement job.
Replacement is also when permit and strapping rules apply. See our guide to water heater permits and strapping in the Fresno and Clovis area.
Call a licensed plumber if water is pooling around the tank, the drain valve will not open or leaks, there is heavy rust at the fittings, or you are unsure about handling gas or electrical connections.
The Department of Energy says most storage water heaters last 10 to 15 years. Rheem says about 10 years for conventional tanks.
The City of Fresno's 2025 report lists average total hardness of 129 mg/L. The USGS scale calls 121 to 180 mg/L hard.
Rheem recommends once a year, or every 6 months with hard water. The Department of Energy guide suggests draining a quart every 3 months.
Not always. Rumbling or popping usually means sediment, which flushing can sometimes clear. Noise that continues after flushing is worth a professional look.
Central Valley Water Heater is a free referral service, not a contractor. Request a free quote from a local plumber.