How to Repair / Replace Broken Pressure Relief Valve on a Water Heater

Broken Pressure Relief valve can flood your basement, increase you energy spending, and in the works case, it can explode, and pose serious health risks!

You should test your pressure relief valve every 6-9 months (this takes only 3-5 minutes), and if it starts leaking, replace it IMMEDIATELY!


Testing Pressure Relief Valve

It is very easy to to test if your pressure relief valve is working properly. You need to take appropriate safety measures, such as using gloves and safety goggles, and just overall be careful and use proper judgement, because water in your tank is VERY hot, and you can easily burn/scald yourself if you are not careful.

To test the valve, you will need a small container – about 1/2 gallon. Once you have your gloves and goggles on, unscrew/remove drain tube off the valve.

Place water container directly under valve outlet (which should be facing down).

Now open the valve slightly (about 60 degrees from its original position). Be sure not to open it all the way, or HOT water will start pouring down.

When you open the valve, the water should start coming out rapidly, under pressure, and you will hear hissing noise. This means your valve is working properly.

If water is not coming out – valve is broken.

Also See: Water Heater Replacement Price Calculator

Using this tool you can estimate the cost of installing new Tankless or Tank Water Heater. Gas or Electric, 40, 50, 75 gallon, Power Venting options, and even locally adjusted pricing. It takes 15 seconds to get an instant price quote!

Now release the handle and water should stop coming out. If water does not stop pouring or dripping – the valve is broken. Yo need to replace it! Here is how to test your pressure relief valve:


HOW to Fix / Replace Broken Pressure Relief Valve:

First – be VERY CAREFUL – water in the tanks is VERY HOT. I’m not responsible if you injure yourself … wear gloves and safety goggles, and use utmost caution. If you do not feel comfortable doing this yourself, contact a local plumber.

STEP 1 What you need to do, is shut off the cold water intake AND gas (dialer on the water heater control) or circuit breaker for the heater (if electric).

Then connect a water hose to BOTTOM outlet. Put hose in 5 gallon bucket or run outside your basement. Again, WATER IN THE TANK IS STILL VERY HOT!

Drain about 5-10 gallons (depending on how high up the pressure valve is).

STEP 2 Once you drain the water, remove the discharge tube / pipe off the relief valve.
Gently open pressure valve HALF WAY (not all the way) to see if water still coming out of it. Put a small bucket or container right under the valve.

If water is coming out, drain another 5 gallons, and repeat.

Once water stops coming out, use plumbers pipe wrench to unscrew the valve.

STEP 3 Now go to Home Depot / Lowe’s or other local home improvement store and buy a new valve with the SAME pressure setting, and a roll of teflon tape.

When you buy your parts, put teflon tape on new valve threads clockwise, and screw in new valve tightly.

You can also get one online.

Here are two options:

Be sure to get the right size, or you will have to go get a replacement!

STEP 4 Now open cold water and put gas setting back to normal (or turn on circuit breaker if electric).

Once tank is full, again gently open pressure relief valve and let a little water out (2-3 ounces). Remember, water will be hot, so be careful.

Once you drain 2-3 OZ, and close valve back, see if water is still coming out. It should not!

If all is good, put discharge tube/pipe back on. You are done!

You should test the pressure valve avery 6-9 months! Just repeat the open / drain 2-3 oz procedure, to make sure the valve is good.

That’s it! You are now a DIY water heater specialist!

If you want to know how much a new water heater costs, see our pricing guide.

4 thoughts on “How to Repair / Replace Broken Pressure Relief Valve on a Water Heater

  1. Oscar O'Malley

    I like that you mentioned using Teflon tape when installing the new valve to reduce the possibility of leaking. My parent’s water heater was having problems a few days ago, and a valve broke. Since it was an emergency situation, we had to hire a contractor to get it fixed. Thanks for the tips-should it happen again I’ll know how to fix it!


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