Hot water is one of those things we often take for granted, until the moment it’s gone, of course. You turn the knob on your shower, expecting a steamy spray of water, and instead, you’re met with a lukewarm trickle and a strange rumbling sound coming from the basement. More often than not, the culprit behind these issues is something surprisingly simple: sediment buildup in your water heater tank.
What exactly is this sediment? It’s a collection of minerals, primarily calcium and magnesium, that are naturally present in our water supply. When water is heated, these minerals separate and settle at the bottom of the tank, forming a thick, sludgy layer. This is especially common in areas with hard water, like Arizona. Over time, this layer of sediment can cause a host of problems, including reducing your system’s efficiency and even leading to costly water heater repairs.
Because sediment can have such long-lasting consequences, flushing your water heater tank annually is one of the most important maintenance tasks you can perform as a homeowner. If you’ve never done it before, the idea of draining that large metal tank can certainly seem daunting. Fortunately, we’re here to simplify the process and empower you with the knowledge to do it safely and effectively.
Follow our step-by-step guide to properly remove that pesky sediment from your water heater tank and enjoy improved performance.
Tools and Materials Checklist
Having everything you need on hand before you start flushing your water heater tank will make the process go much more smoothly. So, be sure to gather the following supplies:
- Garden Hose (choose a standard hose long enough to reach from your water heater’s drain valve to a floor drain, utility sink, or outside area where you can safely discharge hot, sediment-filled water)
- Bucket or Pan
- Channel-Lock Pliers or Wrench
- Flathead or Phillips Screwdriver
- Work Gloves
- Safety Goggles
- Towel or Rags
Step-by-Step Guide to Flushing Your Water Heater Tank
Follow these instructions carefully for a safe and thorough flush. This entire process can take anywhere from 1 to 2 hours, so plan accordingly.
Step 1: Turn Off the Power or Gas
Never drain a water heater while it is still powered on. Doing so can cause the heating elements to burn out in an electric model or damage the gas components.
- For an Electric Water Heater: Go to your home’s circuit breaker panel and find the breaker that controls the water heater. It should be a double-pole breaker, often labeled “Water Heater.” Flip it to the “OFF” position.
- For a Gas Water Heater: Look for the thermostat control knob on the front of the unit. Turn it to the “PILOT” or “OFF” position. This will stop the main burner from igniting. You should also shut off the gas supply by turning the nearby gas valve handle so it is perpendicular to the pipe.
Step 2: Shut Off the Cold Water Supply
Locate the cold water inlet pipe, which is typically on the top right side of the tank and may be labeled or marked with a blue ring. There will be a shut-off valve on this line. It could be a lever-style ball valve or a gate valve with a round handle. Turn the valve clockwise to shut off the water flow into the tank.
Step 3: Connect the Drain Hose
Carefully attach one end of your garden hose to the drain valve located near the bottom of the water heater tank. Make sure the connection is secure to prevent leaks. Run the other end of the hose to your designated drainage area. Be aware that the water that will be coming out will be hot and may contain a significant amount of sediment, so choose a drainage spot that won’t be damaged, like a gravel driveway or a floor drain.
Step 4: Let the Air In and the Water Out
To allow water to flow freely from the tank, you need to let air in to break the vacuum. Go to a sink or tub inside your house (preferably on an upper floor) and turn on the hot water tap. You’ll hear some sputtering as air enters the system.
Next, open the temperature and pressure (T&P) relief valve on the water heater itself. This valve is usually on the top or side of the tank and has a small metal lever. Lift the lever so it stands straight out. You should hear a hissing sound as air enters the tank.
Now, you’re ready to drain. Using your pliers or by hand, slowly turn the handle on the drain valve counter-clockwise to open it. The hot water will begin to flow out through the hose.
Step 5: Flush Out the Sediment
Once the tank is empty, the real flushing begins. With the drain valve still open, briefly open the cold water supply valve for about 15-20 seconds. This will send a blast of cold water into the tank, stirring up the sediment on the bottom.
Let any murky water drain out completely. You may need to repeat the process of opening and closing the cold water supply valve several times before the water starts running out clear.
Step 6: Close Up and Refill
Once you’re satisfied that the sediment is gone, you can begin refilling the tank:
- Close the drain valve at the bottom of the tank securely.
- Disconnect your garden hose.
- Close the T&P relief valve by pushing the lever back down.
- Leave the hot water tap open in your sink or tub. This is important as it will allow air to escape the tank as it fills.
- Fully open the cold water supply valve. You will hear water flowing into the tank. Wait until you have a steady, air-free stream of water coming from the open faucet inside. This indicates the tank is full. Once it is, you can turn off that faucet.
Step 7: Restore Power and Enjoy!
Double-check for any leaks around the drain valve and pipe fittings. If everything is dry, it’s time to get the heat back on.
- For an Electric Water Heater: Go back to your breaker panel and flip the water heater’s breaker back to the “ON” position.
- For a Gas Water Heater: Turn the gas supply valve back on (handle parallel to the pipe) and set the thermostat back to your desired temperature, following the manufacturer’s instructions for relighting the pilot if necessary.
It will take some time for the water to heat up, but you’ve just successfully extended the life of your water heater, so take a few moments to celebrate a job well done!
Need Help With Your Water Heater? Call Cool Willy’s Plumbers!
If you’ve flushed the tank and your system is still causing problems, or if you’re not comfortable performing this maintenance task yourself, don’t hesitate to call the licensed plumbers at Cool Willy’s Air & Plumbing. With over 30 years of experience serving our community, we have seen it all and can quickly flush sediment out of a water heater tank. We can even identify any potential issues, such as a faulty heating element, a malfunctioning thermostat, or a tank that’s reached the end of its life so that you don’t have to worry about disruptions to your hot water supply.
Reach out to Cool Willy’s Air & Plumbing today, and let us get your system back in top condition! We would also be happy to help you with a water heater replacement if the timing is right.