If your Rheem water heater’s drain valve is leaking or doesn’t allow for good water flow, you should replace it. And this article on Rheem Water Heater Drain Valve Replacement will walk you through a step-by-step guide to change the drain valve. So, continue to read.
Table of Contents
Rheem Water Heater Drain Valve Replacement: The How-To Steps
In this chapter, I will walk you through three easy-to-follow steps to replace the Rheem water heater drain valve successfully.
Step 1. Equipment You Need
You should have the following pieces of equipment to replace the Rheem Water Heater Drain Valve:
- A new drain valve
- Adjustable wrench
- Teflon tape
- Flat blade screwdriver
- Garden hose
- Rags or towel
I recommend you go to the Rheem official website and choose a specific drain valve that fits your current water heater.
Don’t forget to turn off the electric supply to your electric water heater at the circuit breaker. On the other hand, if you have a gas water heater, turn the gas supply off.
Step 2. Drain Your Rheem Water Heater

Use a garden hose and attach it to the drain valve at the bottom of your water heater. Then, run the other end of the hose to the nearest floor drain or outside of the house. Many people use a bucket to collect the water. But I highly suggest you to not do that as there is a lot of water in the tank.

Now, locate the shut-off valve, which you can find at the cold water inlet line and shut it off.
Next, open a hot water faucet somewhere in the house to let the system relieve the pressure inside the tank.

Afterward, use the flat blade screwdriver to open the drain valve to let the water drain.
Precautions: The water will be hot. So, be careful and ensure there is no one near the drain hose so that they don’t get scalded.
Once all the water is drained out, close the drain valve and remove the hose from it.
Step 3. Remove The Drain Valve & Replace It
Finally, pull out the drain valve using an adjustable wrench. Some additional water may come out once the drain valve is removed. So, get some rags or towels to wipe away the water spills.
Now, you are ready to replace the drain valve.

Use Teflon tape to seal the threads of the new drain valve. Lastly, install the valve and tighten it by hand and use the wrench to finish tightening.
After completing the installation, ensure the new drain valve is at close position. You can now fill the water tank. Before that, make sure you open the cold water supply valve. Also, turn the hot water faucet off when you get a steady flow of water. And lastly, turn the power back on your water heater or the gas supply.
You may need to relight the pilot. So, check the manual and relight the pilot light before starting the water heater.
FAQs
Can you replace water heater drain valve without draining?
Yes, it’s possible to replace the water heater drain valve without draining. But you should turn the water heater off for about 12 to 24 hours to let the water cool. Otherwise, it will burn your skin. However, I don’t recommend you replace the drain valve without draining the tank as it will flood the surface as there is a lot of water in the tank.
Can you remove the plastic drain valve from the water heater?
Yes, you can remove the plastic drain valve from the water heater. But it’s a bit tricky to pull out the valve as it may break off as it’s fragile compared to the brass one. So, handle it gently.
Why is my water heater leaking from the drain valve?
If the drain valve gets deteriorated over time, water will come out of it. Therefore, if the gasket of the valve is at fault or gets cracked, water will leak into it. In this case, replacing the drain valve with a new one will be an easy solution.
How much does it cost to replace a drain valve on water heater?
The average price of a drain valve is $13 to $15. If you replace the valve professionally, you should spend between $100 to $150. However, you don’t need any additional skills to change the drain valve. Just follow the guides we mentioned to replace the Rheem water heater drain valve.
Where is the drain valve on a Rheem hot water heater?
The drain valve on a Rheem hot water heater is located at the lower part of the tank. Specifically, you can find it at the right side of the gas control valve on the bottom part of the tank.
Are all hot water drain valves the same size?
The standard size of water drain valves is ¾”. In short, most hot water drain valves come in this size.
End-Note
Any homeowner can replace the drain valve of his Rheem Water Heater. I broke down every step you need to follow to change the old drain valve.
Here, I break it down briefly again to replace the Rheem water heater drain valve:
- Turn off the electric supply or gas supply to your water heater.
- Attach a garden hose to the drain valve at the bottom of your hot water heater. Then, place the other end of the heater to the nearest floor drain.
- Use a flat-blade screwdriver to open the drain valve and let the water drain.
- Use an adjustable wrench to remove the drain valve.
- Replace the old drain valve with a new one and install it.
Read Also:
- Rheem Water Heater Gas Valve Problem
- Rheem Water Heater Leaking
- Rheem Tankless Water Heater Troubleshooting Manual

Eric Alvarez is an HVAC guy based in El Paso, Texas, United States. He obtained his Bachelor of Science degree from the University Of Texas at El Paso. Years of experience in the HVAC field have taught him many lessons, not the least of which is that the value of quality and knowledge far exceeds any promised initial savings. He has a good standing reputation for superior skills in heating, air conditioning, hot water tanks, and indoor air quality systems.
My Rheem “Performance” electric heater has a PLASTIC drain valve very different from the brass one shown in video there is a 2″ plastic collar around drain. I followed steps listed by water from tank did not drain. Could the valve be clogged ?? What else shd I try before replacing the plastic valve ?? Thanx.
Bewildered Bob
Yes Bob, it’s pretty challenging to remove the plastic drain valve out of the water heater. And the worst part is- it may break when trying to unscrew that. I highly recommend you replace the plastic valve with a brass one as it doesn’t cost you a lot of bucks. You can check out this video, which will show you how to replace the plastic drain valve:
https://www.youtube.com/watch?v=tbPnxKCClSA
Did you open the Pressure Release Valve? It’s located by the brass drain pipe. Pull it up and water should flow. Later put it back down.