How To Drain A Water Heater

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Many people are unsure of how and when to drain and flush their water heater. This article provides information on the best time when water heater tanks should be drained, the steps you need to follow in this process, how long it takes and other crucial information to know. You know it probably needs a replacement when your water heater is making noise when water is off.

Read on for answers to more of your questions about how to drain a water heater.

Steps to follow when draining a water heater

If you have an electric-powered model that gets its energy source through direct line voltage, do not turn it off at the breaker box until you have first turned off all of its interior switches. 

Next, open the water heater's drain valve.This is usually located near the bottom of the unit in a vertical position, with a hose connected to it that leads to an opening outside your home or building through which all the water can be drained. These drain valves are released either by hand-tightening them or by using an adjustable-width wrench. The type of valve you have will determine how much effort you need to put into opening it.


Once opened and draining freely, leave the drain valve open until there is no more clear water coming from within the tank — this could take anywhere from one to 12 hours depending on how full your tank was when you started this process and what kind of system you have at home — and then close that valve before turning the power back on to your water heater.

Next, flush out the tank by flushing it with two gallons of freshwater for every gallon of water that was drained from it. This step is crucial because if you don't do this properly — in other words, if you just leave everything connected and turn the power back on to your system without flushing those lines — then you risk allowing dirty or contaminated water into a fresh source when your tank refills with clear or new water. 

To ensure that you are flushing all contaminants out of the pipes leading from and into the hot-water heating tank, run cold tap water through faucets throughout your home for at least three minutes. 

Considerations when draining a water heater 

Draining a water heater might also involve cleaning out sediment from tanks and heating elements, removing corrosion, or replacing anode rods in the tank. Before you do, ensure that you’ve tested your water heater to ensure that draining it is the right process to follow.

This process involves draining all of the water out of a water heater and replacing it with a chemical treatment for scale control, rust prevention, or other reasons such as removing sediments that build up over time. And you'll have to keep doing this as long as your water heater lasts

This is a good idea to drain and flush your water heater tank if you notice an increase in the amount of sediment that accumulates at the bottom of your water heater. 

Why You Should Consider Draining Your Water Heater Tank

A homeowner may sometimes need to drain everything out of his or her water tank and flush it with fresh water for several reasons, such as to remove sediment buildup at the bottom of the water heater tank. Sediment can build up over time from poor filtering systems and scale accumulation in some areas around your home. This can cause low hot water pressure or dirty-looking, cloudy-colored hot waters that will not lather properly when using soap. 

Another reason for draining a water heater might be to prevent corrosion in a damaged steel tank (including cast iron). Corrosion on the outside walls of these types of tanks is often caused by leaks that come into contact with air. When it comes to corrosion, there are two different types:

Internal corrosion is a form of rust that occurs on the interior side of the tank. 


External corrosion moves from the outside of the tank inward, attacking joints and welds.

It’s crucial to clean out deposits inside your water heater's storage tank which might be clogging flow through the outlet valve or thermostat, resulting in poor temperature regulation. 

Signs that it's Time to Drain Your Water Tank

Water heater tanks need to be drained and flushed if you find any of the following conditions inside your tank:

* A build-up of sediment deposits at the bottom of the tank; this is often a result of water with high levels of minerals or chemicals flowing through the system.

* Low hot water pressure coming from showerheads, dishwashers, or faucets.

* Dirty-looking, cloudy-colored hot waters that won't lather when using soap. 

* Foul odors coming from your hot water system; these may only get worse over time as they build up in the heater's distribution lines throughout your home.

Muddy brown or rust-colored sediments are usually a sign that your tank needs to be cleaned out and refilled with fresh, clear water — sometimes referred to as “distillate.” This can be achieved by draining the water heater tank and refilling it with new, clean, or distilled water.

sediments in pipe
Image Credit: Kitchen Infinity Photo

Steps to follow before you start draining your water heater

If you're thinking about draining your water heater, follow these basic steps to avoid potential problems:

* Make sure all home fixtures are turned off and the water has been shut off at the main source before draining your tank.

* Have a container under the drain valve of your heater to catch water as it drains from the tank; this will ensure you don't lose any sedimented particles or waste into either the fresh or waste lines which may cause contamination.

* Remove loose sediment in the bottom of your water heater by using a pail, mop, or wand attached to a garden hose that is connected to your drained tank's outlet tube if possible.

* Use bleach-based cleaners on rust stains or lime deposits around welds and joints on storage tanks. These types of cleaners can be found at hardware stores and home improvement shops.

* Flush your hot water tank with a mixture of vinegar or baking soda (depending on the type of corrosion to be treated) and distilled water, which you can often buy at drugstores or grocery stores. If you're adding these chemicals, make sure all fixtures in your home have been turned off before draining the tank.

If you don't want all this hassle, you can go for a tankless water heater. It obviously has its pros and cons but its working is easy!

Final thoughts on how to drain a water heater

A water heater tank should only be drained when it is no longer performing as expected, which may include murky hot waters or a significant reduction in the amount of hot water being produced.

Before conducting this task yourself, check with your local municipality to see if there are any guidelines that you need to observe or follow surrounding draining and refilling of your hot water system's storage tank.

Finally, if you decide that it’s time to replace your water heater all together, consider these best water heaters in the market today before making your choice.

Dino Paccino

Dino Paccino

Dino is a lifelong writer and home improvement specialist. He enjoys bringing cutting-edge information on home renovation and remodeling to Kitchen Infinity.

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