How To Drain A Water Heater

how to drain a water heater

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Can you hear that popping sound? It may be coming from your basement or garage. If your water heater hasn’t been drained recently, then it probably means you’ve got hard water buildup that you don’t even know about. It needs to be drained if it’s going to return to proper working order. Do you know how to drain a water heater?

The process is less daunting than you might imagine. Draining a water heater can take less than half a day and will help soften the water that you and your family use in your home. Many who thought they couldn’t ever accomplish the task themselves have learned how to drain a water heater in next to no time. The key is to approach the process step by step.  

Why You Need to Know How to Drain a Water Heater

“Hard water” is water that has high levels of minerals. Depending on the water source in your city or local municipality, you might have “soft water” with a relatively low-level mineral content or you might have especially hard water. If you’re unsure of the water quality in your area, check state or local websites for more information.

Over time, minerals from hard water can build up in your system, meaning you’ll need to know how to drain a water heater if you want to keep yours functioning properly. While some people neglect to do this routine task, it’s something you should do at least every other year if not annually.

Sediment Buildup

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If you have high concentrations of minerals in your water, then that means that sediment is building up in your water heater. So why is this such a bad thing? Sediment buildup significantly reduces the life of your water heater. Sediment is just another word for mineral buildup. It might come from the water source or sand that gets into the water lines.

A typical water heater can last around 10 years before needing to be replaced. During that time, it’s easy to forget that sediment deposits are building up in your system because the signs are easy to miss or ignore. You might hear a few pops or a groaning sound coming from your water heater when someone turns on the shower, but aside from that, you’ll get few warning signs.

If your water heater is gas-powered, the sediment can collect in a thick gunk inside your water heater. Since the sediment doesn’t always settle evenly, it can form hot spots which cause the lining of your water heater to prematurely erode. Electric heaters aren’t any better off. You’ll face problems from the lower heating unit caused by sediment.

If you’ve just moved into a house with a water heater that you suspect hasn’t been serviced in years because you think the previous owners didn’t know how to drain a water heater, or you’ve had the same water heater for years and think it must be overdue, proceed with caution. There may be so much sediment sitting in the tank that it will clog the drain valve as soon as you open it, which can create a real mess. To avoid having to call a professional to fix the problem for you, you can follow the instructions listed below.

Buying the Necessary Parts

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Many of the tools you’ll need to drain your water heater are already in your home. You may not even need to invest much money at the hardware store though you may need to buy a replacement drain valve if your current valve is damaged during the unclogging process or has become eroded.

Grab a bucket to place underneath the drain valve, some rags, a garden hose long enough to extend outside your home, and a pair of slip-joint pliers. You’ll also need a hose connector to hook up your garden hose to the drain valve. If your drain valve becomes clogged, you might need a coat hanger.

It’s an excellent idea to have a pair of rubber gloves and some clothes that you don’t mind getting dirty. Draining a water heater can be a messy job, especially if there is significant sediment buildup.

Draining the Water Heater

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Before you can learn how to drain a water heater, you’ll need to understand some basic safety procedures first. Always turn off the heater before proceeding with any repairs or maintenance. You will need to switch the water on the heater off the cold valve for this task.

If your heater is electrically powered, look for the circuit breaker in your home and switch off the power in the garage, basement, or wherever your water heater is in your home. If your heater is gas powered, you’ll probably see a thermostat somewhere on the unit. Look for a setting labeled “pilot” to deactivate the heater.

Look for the drain valve which should be located near the bottom of the unit in most water heaters. You’ll need to connect your garden hose to the drain valve to expel the water inside. Make sure that the hose empties somewhere outside that won’t leave standing water in your home or yard.

If you’re downstairs, turn on the hot faucet on the floor above you to ease the pressure on your water heater. With the hose attached to the drain valve, open the pressure relief valve. The pressure relief valve should be located near the top of the unit. On most units, the relief valve will be a tab you can pull down.  

If you open the valve and sediment clogs the hose, don’t panic. The task has become more complicated, but it is still manageable. If there’s no clog, you can let the water drain completely from the tank. You’ll want to turn on the cold water valve to flush out any remaining sediment. Now close the drain valve and the pressure relief valve so that the tank can refill.  

How to Drain a Clog in the Drain Valve

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So how to drain your water heater if you find that sediment has caused a clog in the line? It’s a bit trickier. To start, wait around an hour to see if the pressure from the tank will dislodge the clog. Turn off the hot water valve upstairs. If after an hour there’s been no movement, then you can use a coat hanger to see if the clog will come free.

First, close the valve and detach the hose from your drain valve. Make sure that your bucket and rags are set beneath the valve to prevent dislodged hard water sludge from spilling out on the floor. Take the coat hanger and bend it into a lance you can insert into the drain valve. Move the coat hanger around the inside of the tank until the water gives way and starts to spill into the bucket.

When water starts to spill out at a steady enough pace to fill the bucket, close the valve and reattach the hose to complete the draining process. This might take repeated attempts if there is considerable debris built up in the tank. When all of the water has been drained, flush out the tank with cold water and refill.

Alternatively, you can use the hose to dislodge the clog. With the hose attached to the drain valve, you can stomp firmly onto the hose about two feet away from the water heater. The displaced air in the hose is then sent up into the tank which can sometimes be enough to dislodge small clogs.

It’s a good idea to use these two methods in tandem, as it usually takes repeated attempts to clear clogs caused by sediment debris. But if you’re persistent, these methods can effectively solve the problem. Specialists can employ top-of-the-line tools, but sometimes a little ingenuity is all that’s needed to get the job done.


Mastering how to drain a water heater is often no more complicated than a lot of other household tasks, especially when you break it down into an easy to follow set of steps. Now whenever a problem arises, you’ll know how to drain a water heater and can pass this knowledge on to family and friends.

To have a repairman come to your house could easily cost $200 or more. If you can handle the problem yourself, you’re not only saving yourself money but you’ll also feel more self-sufficient for having learned a task that might have intimidated you before.  

So if you’ve been putting off draining your water heater, don’t wait. The problem will probably continue getting worse if you don’t tackle it head-on. That doesn’t mean you need to do it right this minute. Take some time to familiarize yourself with the process, find out what you can about your water heater, and gather your tools so you’ll be ready for the job. Home improvement stores are great resources for the supplies you’ll need, and many of the salesmen are knowledgeable and can help you navigate problems you might encounter when carrying out the work.

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