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Water heater flushing 101

Most appliances around the household are regularly used or cycled on a daily or weekly basis and are kept in better shape with regular usage. However, one appliance that does not often see direct use that would perform better after being regularly cycled is your household hot water heater. If it seems like the water in your household is not heating as quickly as usual, or if it seems like the overall capacity for hot water is falling short, there is a good chance that your home’s hot water heater is overdue for a regular drain and flush cycle. While the task may seem daunting at first, it is entirely possible to drain and flush a home’s hot water heater without the aid of a professional, increasing the lifespan of the hot water heater, and getting it back up to its normal working condition without too much effort.

Why Flush a Water Heater?

When a water heater is underperforming, the likely culprit is sediment buildup. Minerals — namely magnesium and calcium — tend to be left behind with regular usage of a hot water heater, building up over time and causing the water heater to struggle to maintain the same consistent output of heat and water that is usually produced. This build-up is particularly noticeable in areas where the water is harder, as there is a greater concentration of minerals present in the water supply. Not only does leaving this mineral sediment within a water heater cause the heater to work harder to try and maintain the same temperature and volume of hot water that has come to be expected from the heater, but it leads to the heater wearing and breaking down much faster than normal as the sediment wears against the inside of the heater’s piping and tank. If a hot water heater is flushed annually, it will help maintain the lifecycle of the water heater overall, and push off the costly burden of a full hot water replacement.

Steps to Drain & Flush a Water Heater
1. Turn the Heater Off

This seems self-explanatory, and it largely is — before doing any major service on a water heater, turn it off. If the heater is electric, flip the power switch to “off”. If it is a gas heater, flip the switch to “pilot” mode. Then, allow the water within the heater to cool down.

2. Turn off the Water Supply

Generally located near the top of the heater, close off the cold water intake valve to the heater by turning the valve 90 degrees. Cutting off the cold water supply to the heater will prevent from continually trying to fill and drain while you continue through the next steps.

3. Turn on a Hot Water Tap

Find a nearby faucet, and turn on the hot water. Let it run while you continue to drain and cycle the hot water heater. This will prevent a vacuum from forming in the pipes of the heater, allowing the heater to drain easier.

4. Attach the drain hose

On the side of the hot water heater is a drain valve. Attach a hose to this valve, and run the other end into a drain or large bucket, to prevent the heater from potentially flooding part of your home!

5. Open the drain valve

Turn the valve to “Open” and allow the tank to drain until the water runs clear. This may require a flathead screwdriver (to open the valve) and could take several bucket-loads (if using a bucket).

6. Flush the Tank

Re-open the cold water supply valve, and let the cold water run through the tank. Opening and closing the valve several times will push the remaining sediment out of the tank.

7. Turn the Heater Back On

Once all of the sediment has been removed from the water heater, close the drain valve, remove the hose, reopen the cold water supply valve, and turn the water heater back on. Wait for 20–30 minutes for the hot water to return to temperature, and turn on the hot faucet at a nearby faucet to test that the heat has returned.

a man with a confused look holding a wrench and socket

Once you’re certain that the hot water has returned to the correct temperature, then you can be certain that the drain and flush are complete. As mentioned before, this is an annual task, so it doesn’t need to be completed (relatively) often. Of course, reading through these steps may make this seem like a straight forward task, but actually completing it within your own home can be much more tricky. If you are ever in doubt about completing a hot water heater drain and cycle, contact a plumbing professional. For example, the experts at Duane Blanton Plumbing are always available to troubleshoot any plumbing issue that could arise and are available to jump in and take care of any plumbing task you could imagine. One quick phone call away, reach out to the licensed professionals of Duane Blanton at (815) 781-2567 or schedule with them online through their online scheduling portal. Whether on your own, or with the help of a licensed Duane Blanton technician, get the most from your home’s water heater by keeping it in the top working condition, and make sure it’s flushed once a year!

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