The water heater helps ensure a continuous supply of hot water for everyday tasks. Your water heater works hard all year, so it is important to conduct regular maintenance to keep this appliance in great condition. One of the main steps in maintaining your water heater is flushing the unit. But how often should you flush the water heater, and what does this process involve? A look at the recommended scheduling for flushing a water heater can provide insight on how to ensure the unit’s peak performance and maximum longevity.

What Is Water-Heater Flushing?

A water heater is the main source of hot water for all plumbing fixtures in the home. Depending on the hardness of your water, minerals separate from heated water and accumulate on the bottom of your tank over time. Plumbers help eliminate the accumulation of mineral deposits, sediment, debris, and grime via a process called water-heater flushing. A trained plumber first drains the water heater and then uses specialized equipment like industrial-grade jets or hoses to scour away minerals, rust, and sediment.

How Often Should I Flush My Water Heater?

Experts recommend flushing the water heater at least once per year. This is the recommendation regardless of whether you have a conventional water heater or a tankless water heater. If your household has hard water, you may need to flush the appliance twice a year. The typical schedule for biannual water-heater flushing includes once in the fall and once in the spring. If you live in an area with extreme water hardness, you can consider flushing your water heater several times a year. The U.S. Geological Survey (USGS) defines water hardness in terms of the concentration of mineral carbonates in water. Scientists measure this concentration in parts per million (PPM), milligrams per liter (mg/L) grains per gallon (GPG). The USGS classifies water hardness into four categories:

  • Soft water – fewer than 60 PPM or 3.5 GPG
  • Moderately hard water – between 61-120 PPM or 3.56-7.0 GPG
  • Hard water – 121-180 PPM or 7.1-10.5 GPG
  • Very hard water – greater than 180 PPM or 10.5 GPG

Minerals like calcium carbonate and magnesium carbonate produce limescale that adhere to the interior of your water heater and requires professional flushing for removal. If too much limescale is inside the water heater, the appliance can struggle to heat water or maintain optimal temperatures. Similarly, if you live in a region with high levels of geological sediment in the water, you may also need to flush the appliance more often. Common types of geological sediment include limestone, chalk, and gypsum. Solid dirt particles can clog heating elements, eventually resulting in the absence of hot water in the home. Finally, some localities mail annual water supply reports to homeowners. These reports describe the groundwater source and potential mineral or sediment content. Speak to a local plumbing company if you need help interpreting your annual report.

What Happens If I Do Not Flush My Water Heater?

If enough sediment and minerals have accumulated in the heater, you may start to encounter issues like slower water-heating speeds. Mineral carbonates can also react with the metal of your water heater and cause corrosion. This can lead to breakdowns. Eventually, sediment and debris can permanently impair the unit and require a premature replacement. According to the Department of Energy, the life expectancy of a conventional water heater is 10-15 years, and the potential lifespan of a tankless water heater is around 20 years. Regular flushing can help enable the appliance to live up to its full potential. Finally, flushing the water heater is also a safety issue. Your water heater contains a temperature-and-pressure relief valve. Also known as the T&P relief valve, this component prevents the appliance from building up too much internal water pressure and bursting. It does so by releasing excess steam and pressure at regular intervals. Unfortunately, the minerals and sediment from hard water can clog or block this T&P valve. Regular flushing removes limescale and debris from the valve and helps prevent plumbing emergencies.

What Are the Signs I Need to Flush My Water Heater?

If you still have questions about how often to flush your water heater, there are also signs that indicate it is time to complete this task. These signs include lack of hot water, bad odors or smells, low water pressure, and higher utility bills.

Lack of Hot Water

Water heaters that are clogged with minerals or sediment take longer to heat up liquid. If your water heater needs to be flushed, your hot water supply may end up unheated or lukewarm. Because limescale and debris can block heating elements and create a type of insulation around the heater tank, you may also experience inconsistent temperatures while completing everyday tasks. For example, if your shower goes from scalding to cold to scaling again, it may be a sign of uneven performance of your water heater. A plumber can determine the exact culprit and flush the appliance as necessary.

Foul Odors or Strange Taste

Water that smells or tastes bad can indicate the presence of bacteria. These bacteria can multiply if the water heater does not get hot enough to kill the microorganisms. For example, bacteria called Legionella thrives in tepid water and can cause a type of life-threatening pneumonia known as Legionnaires’ disease. Other bacteria that can multiply in lukewarm appliances include Pseudomonas and E. coli. Pseudomonas can exacerbate skin ailments and respiratory issues, and E.coli can cause deadly gastrointestinal illness. If your water is lukewarm and you notice foul odors or unusual tastes from your hot water faucet, schedule an appointment with a plumber for investigation.

Strange Noises

When debris builds up inside the water heater, the particles can bang against the inside of the appliances and create unpleasant sounds. You may also hear popping, banging, or hissing noises as the heating elements struggle to work in the presence of sediment buildup. A plumber can flush the unit to eliminate these sounds.

Rusty or Discolored Water

Rust-colored fluid from the hot water faucet can mean that the mineral deposits inside your water heater have begun to corrode the unit. A plumber can flush the water heater and rusted elements like the anode rod if necessary.

Low Water Pressure

Excess limescale and sediment can restrict the flow of hot water from the heating unit. If your cold-water faucet has great pressure but the hot-water side has minimal force or flow, contact a plumber to flush your water heater.

Water Heater Leaks

The buildup of limescale and corrosion can eventually weaken the water heater. While the unit may not burst all at once, it can develop cracks at its weakest points. If you notice water pooling around the appliance or leaking from the tank, turn off the unit and reach out to a professional for assistance.

Higher Utility Bills

Mineral deposits and sediment lower the efficiency of a water heater. This causes the unit to work harder to produce the same volume of hot water. The excess heating times draws more power and can result in higher utility bills.

What Are the Benefits of Flushing My Water Heater?

There are many benefits to flushing your water heater regularly. Some of the most definitive perks include the following:

  • Increased energy efficiency
  • Noise reduction
  • Improved heating times
  • Removal of old or stale water from the tank
  • Helps identify related water heater problems like damaged anodes or valves

Contact Us Today

Flushing your water heater is necessary for its effective operation. Once it is time to flush the unit, the professionals can help. Access Heating & Air Conditioning provides water heater services for homes in Boise, ID and surrounding areas. As certified plumbers, we can inspect and conduct maintenance on both traditional and tankless water heaters. In addition, we can perform emergency plumbing repairs and correct any issues with faucets or pipes. Contact Access Heating & Air Conditioning today for all plumbing needs.


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