Water Heater Drain Valve Stuck: The Possible Reasons and Solutions

Water Heater Drain Valve Stuck

The drain valve in the water heater is used to remove the lime and residual build-up inside the drain, repair the drainage, and when the valve is damaged and needs replacement. However, if you live in hard water regions, lime, calcium, and mineral residues will easily develop around the drain valve, forcing it to stop moving and working.

In other words, residual and debris build-up around it causes water heater drain valve stuck occurrence. When the valve gets stuck and eventually clogged, you need to unclog it to help the water drain properly. At times you might even need to replace the drain valve of the water heater.

We will, therefore, discuss the ways to remove a clogged and stuck drain valve and ways to replace the water heater drain valve without draining. So, continue reading the article if you have issues with the water heater drainage.

Water Heater Drain Valve Stuck: Possible Reasons and Solutions Explained

When you decide to clean and flush off the draining pipe of the water heater and see the drain valve isn’t coming off, it can be a little scary. Thankfully, you can solve it at home when the water heater drain valve won’t come off easily.

However, for this, you need to know the reasons for a stuck water heater drain valve. The following sections will answer it.

Mineral And Residual Development:

If you live in a hard water locality, chances are pretty high that the minerals in the hard water will slowly develop around the draining pipe and the valve. Consequently, the minerals and other residues will force the drain valve from moving appropriately.

When the water in your locality has more than 3 grains of mineral, it is referred to as hard water. Unfortunately, 85% of regions in America are affected by different levels of hard water. The problem is more acute in Phoenix, Indianapolis, Las Vegas, etc. Therefore, mineral development due to hard water will cause the drain valve to get stuck.

What’s more unfortunate is that there’s no way you can skip this problem. The only thing you could do is remove the residues from the stuck drain valve of the water heater. Also, the gradual development of the hard water within the pipe will cause clogs.


When the drain valve doesn’t come off due to hard water residues, you will need to eliminate the debris from it to unclog the drain pipe. You will need to remove the stuck drain valve, clean its surroundings and unclog the pipe using a draining snake or auger, or flush off the pipe with white vinegar and baking soda to help it work properly.

Damaged Drain Valve:

Another common reason for a stuck drain valve is damage. The valve may get damaged due to different reasons. It mainly happens when the drain valve is used for years. Also, the water heater plastic drain valve is likely to get damaged more than the metal ones. Also, rust and corrosion can damage the valve is made of metal or cheap plastics.


When the water heater drain valve is damaged, you need to replace it. Thankfully, you can replace the water heater drain valve with a few DIY steps without draining. We will discuss it in the following section.

How to Drain a Water Heater with A Stuck Drain Valve?

When the drain valve of your water heater gets stuck, it can clog the entire draining system of the appliance. Thus, you will need to find a way to remove the clogs. Also, when you see a hot water heater clogged with sediment, you must flush off the sediments to help the device work appropriately.

You will need:

  • Leather-palm gloves
  • Pipe wrench
  • Hose
  • Washer hose
  • Screwdriver
  • WD-40 cleaner

When you are ready with all the essential tools to drain a water heater with a stuck drain, you can proceed to drain it.

Method 1: Observe And Prepare The Water Heater Draining Process

You need to observe it when you see the water heater isn’t draining due to a stuck drain valve. Try to find if the drain valve is stuck due to damages or residual build-ups around it. Also, check if the draining pipe is clogged. Before you drain the heater, you should wear leather palm gloves to avoid any scalding of your hand.

Firstly, align the gas valve perpendicularly with the gas pipe by turning it. You will need to attach a drain hose so that it can connect the valve with the nearest draining spot. You can drain the water heater to a floor drain in your bathroom or basement.

If the drain valve isn’t stuck, you can easily drain the water heater with this simple technique. At this point, it might seem that draining the water heater is easy. However, you often can’t drain the clogged water heater as easily as this “Method 1.” Then, you will need to follow the below-mentioned steps.

Method 2: Repeatedly Step On The Drain Hose

When the water heater doesn’t drain in “Step 1”, you need to create an air bubble inside the tank to drain it forcefully. For this, step on the drain hose that you are using. You need to stand around 2 feet away from the drain hose from the water tank.

As you stand on the hose, it creates an air bubble within the tank. It then forces the tank to eliminate the residues and mineral development. You will have to repeat the stepping up and down the process on the hose multiple times to eliminate the residues to unclog the water heater.

Method 3: Opening and Removing a Stuck Drain Valve of Your Water Heater

When the valve is stuck, you need to observe it. If it has been damaged due to corrosion, or residual development, you will have to remove it to drain the water heater. You may use an adjustable wrench to hold on to the valve and forcefully pry it off from the attached point. If you remove it, you will need to replace the water heater drain valve.

However, if you see residual development around it blocking its movement, you need to remove the debris. For this, apply commercial WD-40 cleaner around it and wait for a few minutes. Now, flush off the debris with cold water and try to open the valve.

When you open the drain valve, attach the hose with it. After that, find and open the pressure relief valve or turn off the water heater. It helps the water heater drain easily with the negative pressure not inside the tank anymore.

The following steps will help you know how to open a water heater drain valve.

  • Before you attempt to remove the stuck drain valve, you must turn off the water heater. Then, wait for 24 hours to allow the heater to cool off properly.
  • Connect the wrench with the valve and start turning it gradually. You will see the water heater drain valve dripping when you unscrew the valve. However, hard water sediments will soon clog it.
  • Water will pour through the draining pipe as you remove the stuck drain valve. It will help the water heater to remove the water fully.
  • If you see lime development at the mouth of the valve after removing it, don’t get panicked. You can remove the lime development by swirling a screwdriver inside the valve’s mouth. You need to repeat it multiple times to unclog the drain.
  • Since you have removed the damaged and stuck water heater drain valve, you must also replace it.

Tips On Ways To Replace Water Heater Drain Valve Without Draining

You might try back flushing the water heater to drain it also. However, you must also replace the drain valve when you remove it.

  • First of all, buy a new drain valve for the water heater. You should choose a brass drain valve because it won’t catch rust and corrosion.
  • Before you proceed further, ensure you have turned off the water supply line of the water heater. Thus, there will be a vacuum inside the heater, and water won’t drip from it.
  • You may follow our steps to remove the stuck valve of the water heater in the previous section. Before you mount the new valve, wrap its threads with Teflon tape.
  • You may clean off inside the pipe using a draining snake or auger. It will help you clean the debris from inside the pipe also. Alternatively, you can pour baking soda and white vinegar inside the pipe and flush it off with hot water after a few minutes.
  • Now insert and mount the new drain valve. After that, you might connect the drain hose to drain the heater once again.

Frequently Asked Questions:

Can you remove the plastic drain valve from the water heater?

Yes, you can remove the plastic drain valve of the water heater. Nonetheless, it can be tricky, so you must be cautious to avoid damage to the plastic valve, or else you need to replace it.

How much does it cost to replace a drain valve?

Usually, a drain valve will cost you around $50 to $200. Also, fixing a leaky drain valve of the water heater will cost approximately $50.

Are all water heater drain valves the same size?

The standard drain valve size for a water heater is ¾ inches. Thus, it is safe to say that all water heater drain valves come in the same size.


When you see the water heater drain valve stuck, you don’t need to be panicked. When you see the water heater drain valve won’t come off easily, you can replace it. You have to turn off the water supply lines and unclog the drain before replacing the stuck drain valve.

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