How to replace a water heater drain valve so you can say goodbye to leaks

Is your water heater leaking, or is it struggling to drain? If so, the problem could be a faulty water heater drain valve. Let’s find out how you can replace it so you can get your unit back in action.

If you need any replacement parts for your appliances, you can enter your model number at AppliancePartsPros.com to order them. Most orders arrive in just two business days, and we have thousands of free guides to show you how to install your new parts.

What does the drain valve do?

The drain valve on a water heater allows the user to drain the tank for maintenance, cleaning, or when the unit needs to be replaced. Over time, the valve can become clogged, worn out, or damaged, which can lead to a range of issues that affect the performance of your water heater. 

Signs of a faulty water heater drain valve

• Leaking at the drain valve
• Difficulty draining the tank
• Damaged or loose valve handle

Common reasons why a drain valve fails

• Sediment accumulation from minerals and hard water. These minerals settle at the bottom and can clog the drain valve.
• Rust and corrosion, which can weaken the valve
• General wear and tear
• Cold weather damage from freezing temperatures can cause water inside the drain valve to expand.
• Over-tightening the valve, which can damage the threads or valve

How to replace a water heater drain valve in 7 easy steps

If you’ve spotted the warning signs of a faulty drain valve and found that it’s damaged or failed testing, you’ll need to replace it.

Note: While we strive to offer helpful advice for DIY appliance repairs, the information in this article may differ from your specific appliance model. Variations in models and configurations can lead to differences in troubleshooting steps, error codes and part replacements. For the most accurate guidance, we strongly recommend consulting the technical sheet for your specific appliance model before beginning any testing or repairs.

1. Turn off the water heater and the water supply. The supply valve is typically located at the top of the unit. If your water heater is electric, turn off the power at the breaker. For gas heaters, set the thermostat to “pilot.”
2. Connect a garden hose to the drain valve for the water heater and direct the other end to a safe drain location. Then open the valve to drain the tank. If water flow is slow, open a hot water faucet to relieve pressure in the system.
3. Use a wrench to carefully unscrew the old water heater drain valve. Be cautious to avoid damaging the surrounding threads on the water heater.
4. Wrap the threads of the new valve with plumber’s tape to keep a watertight seal. 
5. Screw the new drain valve for your water heater into place, but don’t overtighten it.
6. Turn the water supply back on and allow the tank to refill. Open a hot water faucet to let out any trapped air as the tank fills.
7. Turn the power back on or set the gas thermostat to the desired setting. Check the water heater drain valve for leaks once the system is back in action.

Frequently asked questions

Understand your water heater better with these answers to common questions.

Why is my water heater leaking from the bottom?

The most common reason why a water heater would be leaking from the bottom is a failing drain valve. Over time, sediment and mineral buildup inside the tank can clog or damage the valve, which can cause leaks. Another possibility is corrosion in the tank itself, which leads to small holes where water can escape. If the leak is coming from the overflow pipe or temperature and pressure (T&P) relief valve, it may mean that the unit is overheating or has too much pressure inside the tank.

Can I still use my water heater if it’s leaking?

It’s not recommended to use a water heater that is leaking. Small leaks can quickly worsen, and there’s no way to know exactly when the unit would malfunction enough to cause significant water damage or injury if someone was nearby. If the leak is minor and coming from the drain valve, you may be able to temporarily manage it by tightening the valve or draining the tank, but if the leak persists, you’ll have to investigate further or make repairs ASAP.

How do I know if I need to replace the drain valve on my water heater?

You may need to replace the drain valve for your water heater if you notice water leaking from the valve, difficulty in draining the tank, or if the valve handle is loose or broken. Regular maintenance and flushing of your water heater can help extend the life of the valve, but once it starts leaking, it’s typically best to replace it.

Can a leaking water heater cause high water bills?

Yes. Even a small, continuous leak from the water heater drain valve or other parts of the unit can lead to significant water waste over time. It’s important to address leaks as soon as possible to avoid rising utility costs and prevent water damage to your home.

How much does it cost to replace a water heater drain valve?

Replacing a water heater drain valve is generally inexpensive. The cost of a new drain valve can range from $10 to $40, depending on the model and material (brass or plastic). If you choose to hire a plumber, labor costs can range from $75 to $200, depending on your location and the complexity of the job. 

Find more DIY resources

We appreciate you dropping by! Hopefully this guide made it easy to replace the drain valve in your water heater. If you’re still in need of any parts, head over to AppliancePartsPros.com with your model number. Our inventory of over two million parts and quick shipping means that you should get an exact replacement on your doorstep in just a few days. 

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