Water Heater Maintenance Guide — Extend the Life of Your Water Heater

Sediment — calcium and magnesium scale plus rust particles — settles on the tank floor and insulates the heating element from the water above it, causing the unit to work harder and overheat at the bottom. Flushing once a year removes this accumulation. Process: (1) Turn the unit to PILOT or switch off the circuit breaker. (2) Attach a garden hose to the drain valve at the tank base. (3) Run the hose to a floor drain or outside. (4) Open the drain valve and let the tank empty — the water will run cloudy or rusty with sediment. (5) Briefly open the cold supply valve to stir and flush remaining sediment. (6) Close the drain valve, refill the tank, restore power. In hard water areas (above 200 mg/L), flush every 6 months.

The anode rod is a sacrificial magnesium or aluminum rod suspended inside the tank. It corrodes preferentially to the steel tank lining — as long as the anode rod is intact, the tank resists internal corrosion. When the rod is depleted, the steel tank begins to corrode, producing rusty water and eventually leaking. Inspect the anode rod every 3–5 years. The rod screws into the top of the tank (may be under the top cover or sheet metal casing). A rod reduced to the steel core wire, or coated in thick calcium deposits, needs replacement. Replacement cost is $20–$50 for the part — far less than a new water heater.

The recommended water heater temperature setting is 120°F — hot enough to prevent Legionella bacterial growth, cool enough to minimize scale accumulation rate, and safe enough to prevent scalding at fixtures. Settings above 130°F dramatically accelerate scale deposition: the rate of calcium carbonate precipitation roughly doubles for every 10°C increase in water temperature. Settings below 120°F create conditions where Legionella pneumophila, the bacterium that causes Legionnaires' disease, can proliferate in the tank.

The temperature and pressure relief (T&P) valve is a safety device that prevents tank overpressurization — it opens automatically if tank temperature exceeds 210°F or pressure exceeds 150 PSI, releasing water to prevent a catastrophic tank failure. Test the T&P valve annually by lifting the test lever and allowing a small amount of water to discharge through the drain pipe. If the valve leaks after testing, or if it has never been tested and is over 5 years old, replace it — a failed T&P valve on an overpressurized tank is a serious safety hazard.

Schedule a professional service call when you observe: rusty or discolored hot water (anode rod depleted or tank corroding internally), rumbling or popping sounds during heating cycles (heavy sediment requiring professional descaling), water pooling around the tank base (failing tank — replacement is imminent), inconsistent hot water temperature (thermostat, dip tube, or element failure), or the unit is 10+ years old and showing any of the above signs. A professional technician can assess whether repair or replacement is the better economic choice for your specific unit and usage pattern.