What Is a Hot Water Heater Pressure Relief Valve?

What Is a Hot Water Heater Pressure Relief Valve?

To use hot water for handwashing, dishwashing, and your shower, your water heater needs the right amount of pressure. If the pressure is too high in the tank, the water heater could break down. On the other hand, a low amount of pressure in the system can negatively impact the distribution of warm water in your home. So what helps control the balance of pressure? Your hot water heater pressure relief valve. 

What is a Water Heater Pressure Relief Valve?

Sometimes called a pressure relief valve, water heater temperature valve, or T&P valve—your water heater pressure relief valve keeps your water heater from reaching dangerous temperatures. This safety feature can also help ensure there are no leaks in the tank.  

How a Water Heater Pressure Relief Valve Works 

A functioning water heater pressure relief valve will release steam and hot water from the discharge tube to prevent issues in your system.

Here is how a normal water heater works:

  • Your water heater warms up 
  • Water temperatures reach between 120 and 140 degrees 
  • Both the metal tank and the water inside expands

Your water heater can break down when temperatures reach 210 degrees, or when the pressure reaches 150 pounds per square inch (psi). To keep this high pressure and temperature situation from breaking your heater, you need a functioning water heater pressure relief valve. 

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The Process Of Testing a Relief Valve 

Other than lack of hot water, how else can you tell if your hot water heater pressure relief valve is malfunctioning? Give it a test. 

  1. First, ensure the valve on your water heater is shut off. Find it near the cold water feed on top of the tank. 
  2. Next, check the discharge tube to make sure it's firmly attached and place a bucket underneath it. 
  3. With the bucket in place, pull down the metal lever slightly so that a small amount discharges.
  4.  Lastly, release the lever.

If the lever does not snap back to its original position quickly, then your valve is not working properly.  Even if you don’t have a reason to suspect a problem, checking your water heater pressure relief valve can save you time and replacement costs. 

What Is a Hot Water Heater Pressure Relief Valve?

How to Fix Your Water Heater Pressure Relief Valve 

Issues with your water heater pressure relief valve usually come in two varieties—it’s stuck or it leaks. 
Here’s how to fix the issue. 

Valve is Stuck 

A valve stuck in a closed or downward position won’t be able to release heat or pressure building up in the tank. With no relief, the tank can rupture, causing serious damage. 

If the valve is stuck in the upward or open position, water will continue leaking. With nothing to stop the water, you may end up with a flooded home. 

To fix this, try opening and closing the lever a few times. If that doesn’t work or continues to stick, you need to replace it. 

Leaking  Pressure Relief Valve 

Have you noticed puddles of water or spots around your tank? Before replacing the entire system, check your hot water heater pressure relief valve to ensure it's not leaking. It may not be installed correctly in the threaded opening of the water tank.

Steps To Fix This Issue:

  1. Shut off the water heater
  2. Let water heater cool down
  3. Remove valve and rethread into the tank opening

Sometimes the leak is due to sediment or dirt blocking the relief port.

Steps To Fix This Issue:

  1. Place bucket under the discharge tube
  2. Pull back metal spring lever
  3. Water will fall into the bucket

If water is still leaking despite the valve snapping back into its original position, turn off the gas valve. To safely replace the valve, shut off the water.  

For Your Safety

If excess pressure is causing the valve to malfunction—call a local plumbing expert. These situations are dangerous and may require a professional.  

What Is a Hot Water Heater Pressure Relief Valve?

Water Heater Repair & Installation Services 

If you’re experiencing issues with your water heater or want it looked at by a professional plumber, give our team a call by phone at (630) 968-0783 or fill out our contact form. Our technicians offer exceptional water heater repair and replacement services for homes in Downers Grove, Illinois and other areas. In addition, our staff provides other types of emergency plumbing services such as garbage disposal installation, water line installation, drain cleaning, and sump pump repair. Our technicians are committed to helping you resolve issues with your water heater and plumbing system.

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