Plumbing Tips | December 14, 2021

How To Replace A Water Heater Drain Valve (Just 4 Steps!)

On average, water heaters last about 10 years (give or take). And along the way, parts can break down. This usually happens after the warranty has expired. Go figure!

One such part is the water heater drain valve. When it goes bad, you can replace it yourself if you have a moderate amount of DIY plumbing experience. Let me show you how.

Table of Contents

How to Repair a Leaky Water Heater Drain Valve

Before we begin installing a new drain valve, let’s first try to repair it.

Turn the gas control knob OFF and close the gas shutoff valve. If you have an electric model, shut off power at the main service panel.
Close the cold water supply valve and drain the heater completely. Watch the video below for an explanation of how to drain the water heater.
If the drain valve has a removable handle, unscrew it and replace the washer behind it.
Reassemble the handle, refill the tank, and check the valve for leaks.
If the handle cannot be removed, or the drain valve is made of plastic, replace the entire valve. See the next section for instructions.

How to Remove a Water Heater Drain Valve

Fit a pipe wrench over the base of the drain valve and turn it counterclockwise to unscrew the valve from the tank.
If the valve is plastic, first turn the handle counterclockwise by hand, four complete revolutions.
Then, while pulling firmly on the handle, turn the valve handle clockwise six complete turns to free it from the tank.

To drain the tank (one of your first steps), attach a garden hose to the drain valve. Open the drain with a screwdriver. Make sure the hose drains into a nearby floor drain or utility sink.

Assembling a New Drain Valve

Because it is both durable and contains a washer (and can therefore be serviced), a sillcock valve is the recommended replacement for a water heater drain valve.
When selecting the valve, also buy a 3/4- to 1/2-inch reducing coupling to match the valve to the tank.
Wrap pipe tape around the threaded end of the silcock valve and screw it into the 1/2-inch end of the reducing coupling.

A water heater drain valve typically looks like this. However, some have handles while others are made of plastic. But don’t worry, they all work the same.

Installing a New Water Heater Valve

Apply pipe tape to the threaded end of the nipple on the water heater tank.
Screw the coupling and valve onto the nipple and tightest it as much as possible by hand.
Finish tightening the coupling with a pipe wrench.

You can find threaded seal tape (or plumber’s tape) at any hardware store. It’s cheap and provides a lot of value. Taping the threads will create a watertight seal for your drain valve.

Aligning the Water Heater Drain Valve

Fit an adjustable wrench over the body of the sillcock valve (but not over its outlet), and turn it clockwise to tighten the valve. You want the spigot-end of the valve to face down toward the floor.
Refill the tank and relight the pilot (or turn the electricity back on).

In your final step, use an adjustable wrench to align the valve so the faucet end (the spigot where water comes out) points down toward the floor. Don’t place the wrench around the spigot, but do place it on the body of the valve nearest the tank.

Final Thoughts

For some reason, many of our customers believe that water heaters are too complex or difficult to work on themselves. But some parts can be fixed or replaced quite easily.

Follow our instructions and save yourself a lot of money with a job that’s surprisingly easy. A drain valve itself only costs about $10-$30 but the cost of a professional plumber’s time is quite a bit more.

Call 1-Tom-Plumber

Don’t hesitate to contact us here or call us at 1-Tom-Plumber (1-866-758-6237) if you need help servicing or replacing parts on your water heater.

1-Tom-Plumber’s certified team of plumbers and drain technicians respond immediately to any emergency plumbing, drain cleaning, or water damage problem. We also handle the excavation of underground water lines and sewer main lines. Our immediate-response team is available every day and night of the year, even on holidays.