Flush It or Lose It

Tank heaters store 40 to 80 gallons of heated water, and the minerals in that water settle to the bottom as sediment. Over time the sediment insulates the water from the burner or elements, so the heater works harder, gets noisy, and wears out sooner. Draining and flushing the tank clears it out. Rheem recommends flushing most tank heaters once a year, and about every six months in hard-water homes. Always follow your heater's owner's manual.

Tankless units heat water on demand, so there's no tank of sediment to drain. Instead, hard-water minerals form scale inside the heat exchanger. Scale reduces efficiency and can trigger error codes or shutdowns. Tankless heaters need periodic descaling: a descaling solution is circulated through the unit using service (isolation) valves. How often depends on your model and your water hardness, so follow the schedule in your manufacturer's manual.

Homes around Canyon Lake and New Braunfels commonly have hard water, and private wells in the area can run even harder. The calcium and magnesium in hard water are what become sediment in tank heaters and scale in tankless heat exchangers. The harder your water, the more often your heater needs attention, and the faster it wears out when maintenance is skipped. A properly sized water softener can slow that buildup. Learn more on our Water Softeners & Hard Water page.

• Popping, rumbling, or crackling sounds from a tank heater
• Hot water runs out faster than it used to
• Rusty, cloudy, or gritty hot water
• Water temperature that swings between hot and cold
• A tankless unit showing a scale or maintenance error code
• Water around the base of the heater, or dripping from the relief valve line (call a plumber right away)

Many homeowners flush their own tank heaters, but the job involves scalding-hot water, gas or high-voltage electrical connections, and old valves that can start leaking once they're disturbed. Only follow the steps in your heater's owner's manual, and call a licensed plumber if: the drain valve won't open or won't stop dripping; water barely trickles out (heavy sediment); the tank or relief valve is leaking; your tankless unit has no service valves installed; or you're not comfortable working around gas or electrical connections.

Ruben is a Texas licensed master plumber with 40 years of experience serving Canyon Lake, New Braunfels, and the surrounding Hill Country. Speedy's Plumbing can flush a tank water heater, descale a tankless unit, check for leaks, and explain whether maintenance, repair, or replacement makes sense. Call (210) 425-1360 or request water heater service online.