If your water heater came with a cheap plastic valve, you may want to consider upgrading to a brass valve. Thankfully, water heater drain valve replacement is a rather easy task.
If you’re planning on replacing your drain valve, you may wish to make a run to your local hardware store and pick out a new valve while waiting for the tank to cool. Otherwise, order a new valve online so you’ll have it ready for the weekend or whatever day you choose to replace the valve.
Choosing the Right Replacement
There are actually a couple choices to make when getting a replacement drain valve. You can purchase valves in brass, composite, or plastic. Plastic is the cheapest, but also the least reliable of the three. Composite is better for your anode. However, I recommend brass valves, as they last the longest and can handle much higher temperatures than a composite or plastic drain valve.
Another, less clear choice is whether to get a ball valve or a standard. Ball valves have their advantages, but as you are going to be using it to drain sediment, you might prefer to avoid the slightly higher risk of clogging. That said, I still prefer the ball-type valves.
If You CAN Drain the Tank
The best and safest way to change your drain valve is when the hot water tank has been emptied. You will need to shut off the power and gas (if applicable) supply before starting. The process works best if you allow the water to cool for 12 to 24 hours, although you can drain sooner if you wear protective clothing to avoid splashes.
Open the T&P valve and shut off the cold water intake valve when you’re ready to begin. Attach a hose and drain as you would during a normal flush. Leave the valves in their positions after the tank is empty and remove the old drain valve using a wrench.
Prepare the new valve by wrapping some Teflon tape around the threads. This step is a great idea for any threaded water fitting, as the tape creates a tighter seal. Replace the new valve and tighten it with your wrench.
Turn on the cold water intake valve and allow the tank to fill for a few minutes, examining for leaks. Wrapping a paper tower around the drain valve (see also ‘How To Unclog A Drain Valve: The Complete Guide‘) is a good way to spot moisture. If there is no sign of leakage, allow the tank to continue filling. You can turn on a nearby hot water faucet to check the flow.
Once the waster’s coming out smoothly, close the T&P valve and shut off the faucet. Restore the power and gas supplies to the water heater. Finally, dispose of the old valve and allow the tank to do its job.
If You CAN’T Drain the Tank
In the event a clogged drain valve is preventing you from draining the tank, you might be wondering, can you replace a water heater drain valve without draining? The answer, thankfully, is YES.
Provided you have everything prepared, the replacement itself is very quick and thus easy enough to accomplish. Note, however, that this method should not be used when your problem is the drain valve leaking, as the risk of burns would be much higher.
Begin by ensuring every hot water faucet in the house is turned off. This will help ensure any air in the water lines has trouble getting into the tank. As a result, any water loss will create a vacuum that minimizes the amount of leakage. You will want to place some towels under the valve to absorb the leak and wear protective clothing and gloves to avoid getting burned by the hot water.
Wrap a layer of Teflon tape around the threads of your new valve to ensure a snug fit. Gently unscrew the defective valve, being careful to avoid getting splashed by any leaking hot water. Once it’s loose, quickly swap out the two valves and tighten the new one. You can now flush the tank if you so choose.