Water heaters are one of the hardest-working appliances in your home, operating 24 hours a day to keep hot water ready on demand — yet they’re also one of the most neglected when it comes to maintenance. With routine care, a quality water heater can last 12 to 15 years or more. Without it, mineral buildup, anode rod failure, and sediment accumulation can cut that life significantly shorter and drive up your energy bills in the process. In Denver and the Front Range, where hard water is a genuine challenge, water heater maintenance matters even more than in softer-water regions.

Flush the Tank Annually to Remove Sediment

Colorado’s hard water — high in dissolved calcium and magnesium — leaves mineral deposits inside your water heater tank over time. These deposits settle to the bottom as sediment, forming an insulating layer between the burner (or heating element) and the water. The result: your water heater works harder and uses more energy to produce the same amount of hot water, the bottom of the tank runs hotter and degrades faster, and you may hear rumbling or popping sounds as water percolates through the sediment layer during heating.

Flushing the tank annually removes accumulated sediment. This involves connecting a garden hose to the drain valve at the base of the tank, running it to a safe drainage point, and briefly opening the valve to flush sediment out. If your water heater hasn’t been flushed in several years, the sediment may be substantial — in those cases, a plumber can perform a more thorough flush and check the drain valve itself, which can seize up on tanks that have never been serviced.

Check and Replace the Anode Rod

The anode rod is a sacrificial metal rod — usually magnesium or aluminum — suspended inside the tank. It corrodes preferentially so that the steel tank lining doesn’t. When the anode rod is depleted, the tank itself starts to corrode from the inside, leading to rusty water and eventually a leaking tank. Anode rod inspection and replacement is one of the most impactful maintenance tasks you can do to extend a water heater’s life.

In hard-water conditions like those common on the Front Range, anode rods deplete faster than manufacturer guidelines suggest. Checking the rod every two to three years (and replacing it when it’s significantly depleted — less than half an inch of core material remaining) is a reasonable interval. This is a task most homeowners can’t easily do without the right tools and some plumbing knowledge; it’s a natural item to include in a water heater maintenance visit.

Test the Temperature and Pressure Relief Valve

The T&P (temperature and pressure) relief valve is a safety device that opens if the tank pressure or temperature reaches dangerous levels. It’s the last line of defense against a catastrophic tank failure. These valves should be tested annually to confirm they open and close properly. Testing involves lifting the small lever briefly to release a small amount of water; if the valve doesn’t open, or if it opens but doesn’t reseat properly afterward (dripping continuously), it needs to be replaced. A stuck or failed T&P valve is a safety concern and should be addressed promptly by a licensed plumber.

Check the Temperature Setting and Inspect the Unit

The Department of Energy recommends setting water heaters to 120°F for most households — hot enough to prevent Legionella growth, but not so hot that it creates scalding risk or excessive standby heat loss. Many water heaters come from the factory set at 140°F. Dialing it down saves energy; confirming the setting is accurate also ensures consistent hot water delivery.

  • Flush the tank annually to remove sediment
  • Inspect and replace the anode rod every 2–3 years in hard-water conditions
  • Test the T&P relief valve annually
  • Confirm temperature is set to 120°F
  • Inspect the area around the tank for signs of corrosion, rust staining, or minor seepage

When Maintenance Reveals It’s Time to Replace

A maintenance visit sometimes reveals that a water heater is too far gone to justify further investment — heavy internal corrosion, a depleted anode rod that was never replaced, or a tank that’s already 12 or more years old. In those cases, replacement before an emergency leak is the smarter move. Tankless water heaters are worth considering at that point as well — they heat water on demand, last longer than storage tanks, and perform well in Colorado’s altitude with proper sizing.

Done’s plumbing team handles water heater maintenance, repair, and replacement across the Front Range. Visit our water heater maintenance page for more details, or explore water heater repair and water heater replacement if your unit needs more than maintenance. Considering a tankless upgrade? See our tankless water heater page. If hard water is shortening your appliance life, our water quality treatment services can help. Contact Done to schedule a water heater service.