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What to Do When Your Water Heater Pressure Relief Valve Is Leaking

If you notice that your hot water heater pressure relief valve is leaking, then it’s time to replace it. Most home improvement stores carry this replacement part and sell it at a reasonable price. In most cases, you can acquire a new water heater pressure relief valve for about $10 to $15. To fix your water heater pressure relief valve leak, follow the steps below.

  1.  Turn off your unit’s power or gas source and shut off the water running into it as well.
  2. You’ll now want to empty the water from the tank. You only need to drain the water a little below where the pressure valve is located. An easy way of doing this is to turn on the hot water in either your kitchen or your bathroom. The hot will then begin to drain.However, it’s also important to note that whenever you do any repairs to your hot water tank, as with the pressure valve replacement, it’s good idea to flush your tank and clean out the sediment at the bottom of the reservoir.
  3.  Now, release any air pressure that might still be lingering in your tank by raising the handle on the valve. By chance that your water heater has a metal pipe connected to it, you’ll want to remove it.
  4.  Equip yourself with a wrench and begin unscrewing the pressure relief valve. You’ll want to unscrew it counter-clockwise. Be extremely careful when you’re removing your faulty pressure relief valve.
  5.  Apply pipe-thread tape to the threads of your new pressure relief valve.
  6.  Begin to screw your replacement part into the hole. Make sure you are turning it clockwise.
  7. Turn back on your water heater’s power or gas source as well as the water.
  8.  If your water heater is gas powered, relight your water heater’s pilots switch.

If your hot water heater pressure relief valve is still leaking after the replacement, it could be because the valve is releasing some of the extra pressure that has built up within the tank. It’s important to remember that when cold water heats up, it begins to expand. As a result, the excess water will shoot back up the cold-water inlet if there’s not enough room in the reservoir.

The problem is, the water supply piping for your home will most likely have a check valve or a one-way valve imbedded to it. As the water expands and has no place to go, the pressure will continue to build and if left for a long enough period, your tank could explode causing damage to your property.

What’s the solution? Installing an expansion tank is your best answer. An expansion tank provides the water someplace to go when room runs out in the reservoir and should be installed near the water heater tank. In many cases, the expansion tank is installed above the water heater tank.

Kevin L. Sharp


Thursday 3rd of March 2022

I have a Lochinvar 50 gallon electric water heater. We installed it because the old water heater developed a leak in the tank. After installing the water heater a couple days later the pop off valve started leaking. We made sure it all the lines throughout the house have been bled. We installed a pressure regulator on the cold water coming in to the water heater and also replaced a pop off valve. Frustrated because the pop off valve is still leaking. Any suggestions or help? Now this water heater does not have an expansion tank.


Sunday 8th of May 2022

@Richard, Try turning the temperature of the tank down (120 or so) or a expansion tank should do the trick.