Water Heater Leaking from Drain Valve: What Should I Do?

water heater leaking from drain valve
Is water leaking from the drain valve on your hot water heater? This is usually a sign of a failing water heater or often just the valve. In some cases, the leak may be very slow, but this doesn’t mean you can ignore it. If the drain valve fails, all the water stored in your hot water tank will flood your basement. 

Let’s take a look at the common causes of water leaking from your drain valve and what you can do about it.

Why Is There Water Leaking from the Drain Valve?

Water heater drain valves are used to drain the hot water from the tanks, which is a common maintenance task done to remove built-up sediment. It’s always a good idea to confirm the source of the water before assuming it’s the drain valve, though. Make sure the water is not coming from these other areas before you continue:

  • Temperature & pressure relief valve
    • This valve will release water from the tank if the pressure is too high or the temperature is above 210º F. Make sure your thermostat is not set too high.       
  • Leaking tank
    • Old or neglected tanks can develop pinhole leaks at the bottom of the tank, where sediment and minerals collect.
  • Condensation
    • After prolonged hot water usage, condensation can form on the valve as the unit heats up, dripping water onto your floor. To make sure the leak you’re seeing is actually a leak, dry off the valve and don’t use your hot water for a few hours. When you return, there shouldn’t be any water near the tank, which indicates a false alarm—phew!

Once you’ve confirmed the source of the leak as the drain valve, check for these common issues:

  • Worn-out plastic – Some hot water tank drain valves are made of plastic. Over the years this plastic can become brittle, and when the valve is used to empty the drain tank, the plastic can crack, which can cause a leak.
  • Failing gasket – Plastic drain valves also use a rubber gasket that deteriorates over time. This is also a common culprit for leaks.

Fixing a Leaking Drain Valve

Replacing the entire hot water tank drain valve is usually the most reliable fix for a leak. However, you can try and tighten the valve slightly with a wrench to see if the leak stops. Be careful not to overtighten the valve, or the leak could become worse or the valve might break off.

Always use the plumber’s tape (thread seal tape) on the new valve threads. If the valve is made out of brass, you may attempt to replace the gasket and reinstall the valve. We don’t recommend replacing gaskets in plastic drain valves.

Hot Water Heater Drain Valve Replacement

Since replacing a hot water heater drain valve has the potential to 1) scald you and 2) flood your basement, it’s best to leave this job to professionals. You can trust Mr. Rooter not only to replace the valve safely and without flooding, but also to inspect the unit and identify the problem that may have caused the leak in the first place.

In many cases, a leaking valve is caused by sediment buildup in the internal mechanism. Before we replace the valve, we’ll flush the tank, remove the sediment, and install a reliable brand-new drain valve.

Since all our parts and workmanship are guaranteed, you can trust the repair will last. Just call us or request a job estimate online and replace that leaking valve before it becomes a bigger problem.

This blog is made available by Mr. Rooter LLC, for educational purposes only to give the reader general information and a general understanding of the specific subject above. The blog should not be used as a substitute for a licensed plumbing professional in your state or region. Check with city and state laws before performing any household project.