How to Flush Your Hot Water Heater

Do I Need to Flush My Hot Water Heater? Absolutely!

Few modern luxuries rival the indulgence of a lengthy, steamy shower. Yet, amidst your relaxation, do you ever ponder the origins of that warm cascade? Are you aware that without proper maintenance, sedimentary deposits like rust may accumulate within your water heater, potentially compromising your bathing bliss?

The water heater often falls into the category of household appliances taken for granted. Tucked away out of sight, it dutifully fulfills its function for years, sometimes without so much as a second thought. Typically, it only springs to mind when something goes amiss.

However, like any appliance, water heaters demand regular upkeep to optimize energy efficiency and prolong their operational lifespan. A neglected unit might continue providing hot water for a time, but gradually, it will lead to escalating utility expenses and, ultimately, a complete breakdown.
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To safeguard your investment, it’s prudent to enlist the services of a licensed professional plumber for an annual inspection. A competent plumber will conduct a comprehensive assessment for rust, leaks, and other issues, examine the thermostat and valves, replace the anode rod to prevent corrosion, and, crucially, flush the tank.
Yet, this final task—flushing the tank—might be one you consider undertaking yourself, perhaps every few months, depending on your local water's mineral content. Learning how to perform this maintenance chore can yield substantial savings over time, and it's surprisingly straightforward.

Why should I flush my water tank periodically?

Regularly flushing the lime and other sediments from your water heater tank is crucial for improving the heater’s efficiency and prolonging its lifespan. In neglected units, sediment can accumulate and solidify, posing significant challenges for removal. In severe cases, this buildup may necessitate the replacement of the entire water heating unit. However, by adhering to a regular flushing schedule, you can mitigate the risk of sediment-related problems.
Every water source contains a certain level of mineral content. For instance, if you reside in an area abundant in limestone deposits, the groundwater is likely to absorb calcium and magnesium, resulting in the formation of "hard" water.
Hard water generates sediment in the form of limescale, which gradually accumulates at the tank's base. In natural gas heaters, this can lead to uneven heating within the tank, potentially resulting in leaks over time. For electric heaters, scaling can cause damage to the lower heating element. Moreover, sediment buildup can obstruct the drain valve in both types of heaters.
How can you identify sediment buildup? One telltale sign is a popping or rumbling sound emanating from the heater's tank, indicating steam bubbles struggling to rise through the sediment. Additionally, sediment can create hot spots on a gas water heater, posing a risk of tank damage and premature heater failure.

When will I know my water heater needs a flush?

​Fortunately, the water supply to your water heater undergoes some degree of filtration before reaching your home. Otherwise, sediment would swiftly accumulate in your hot water tank, potentially unnoticed for years.
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Over time, you may start to notice a diminishing supply of hot water from the tank before it runs dry. If your water tank is easily accessible, you might observe sediment emerging from the drain valve, unless the sediment has already obstructed the valve.

A word of caution: If you haven’t flushed your water heater in several years, it’s advisable to enlist the services of a licensed plumber. There’s a risk of inadvertently triggering leaks. It's plausible that the long-standing sediment has caused cracks in the tank's bottom. While the existing sediment may currently seal these cracks, draining and flushing the tank could dislodge the sediment, potentially exacerbating the leaks.

We're not suggesting that you should avoid draining your tank altogether, nor are we implying that not flushing it for several years will inevitably result in a leak. However, by engaging a licensed plumber for the task, you’ll have the expertise at hand to address any potential leaks should they occur.

Step 1: Turn off the water heater and water supply. Start by shutting off the cold-water supply valve connected to your water heater. You can find this valve on top of the water heater where the water pipe enters. For older homes, you might need to shut off the main water supply line. If your heater is gas-powered, switch the thermostat to pilot mode. For electric heaters, turn off the power at your home's electrical panel, making sure to identify the correct fuse or circuit breaker labeled for the water heater. It's a good idea to allow some time for the water in the tank to cool down as a precaution.
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Step 2: Connect a garden hose to the drain valve. Once the water heater has cooled, attach one end of a garden hose to the drain valve at the bottom of the heater. The other end of the hose should be placed in a floor drain or outside if possible.

Step 3: Run hot water and open the drain valve. Open a hot water tap closest to the water heater to relieve pressure and help the tank drain faster. Then, open the drain valve to allow water to flow out of the tank. Depending on the amount of sediment or the tank's fullness, this may take some time.

Step 4: Turn the water supply back on to flush the tank. While the drain valve remains open, turn the cold water supply back on to flush out any remaining sediment at the tank's bottom. Repeat this step until the water runs clear.

Step 5: Close drain valve, fill tank, and turn on water heater. Once the tank is drained, close the drain valve and disconnect the garden hose. Ensure the cold-water supply valve is open to allow the tank to refill. Return to the hot water tap you opened earlier, wait for cold water to flow, and then turn it off. Finally, restore power to the water heater by turning on the gas for gas heaters or flipping the breaker for electric heaters. Check for any leaks at the valve, and you're all set.

If your water heater requires it to always be full, refer to the manufacturer's instructions to avoid damaging the heating elements. If you encounter any operational issues, don't hesitate to reach out to us for assistance, and we'll send one of our technicians for an inspection.

What if my tank won’t drain? If your tank is draining slowly or not at all, try opening the temperature/pressure relief valve located near the top of the tank. This valve typically has a lever that you can lift or lower, connected to a pipe extending down to the tank's base. Opening this valve could relieve any potential vacuum inside the tank that might be hindering drainage.

If your tank is severely clogged with sediment, to the point where it's blocking the drain valve, it's wise to seek the expertise of a licensed plumber. They have the necessary tools and knowledge to address the issue effectively and safely. Don't hesitate to reach out to a professional plumber for assistance in this situation.

What exactly are the benefits of draining your hot water tank?

1. Noise Reduction: Over time, mineral or scale accumulation in your hot water tank can lead to noises like banging, crackling, or popping. These sounds occur because the scale layer hardens, making it difficult for water to flow through. Draining and descaling the tank can eliminate these noises, restoring quiet operation.
2. Enhanced Efficiency: Sediment buildup on the bottom of the tank hampers heat transfer, as it forms a barrier on the heater's electrodes. Draining the tank removes these deposits, allowing for improved heating speed and overall efficiency.
3. Reduced Energy Bill: With fewer scales and debris, the water heater operates more efficiently, requiring less energy to heat water. This results in a decrease in energy consumption and, consequently, a lower energy bill.
4. Longer Lifespan: Regularly draining the hot water tank removes scale that can cause stress on the appliance. This helps prevent the tank's metal from overheating, reducing the risk of leaks or failure. Consistent draining and flushing contribute to prolonging the appliance's lifespan.

As for tankless water heaters, they are also susceptible to damage from sediment accumulation. However, the flushing process differs from conventional hot water tanks and typically involves using a pump to circulate water through the system. You can find tankless water heater flush kits at hardware stores for this purpose.