Close this search box.

Water Heater Leaking from Pressure Relief Valve: Causes and Solutions

Note: This post may contain affiliate links. This means that at no cost to you, we may receive a small commission for made purchases.

A leaking water heater pressure relief valve can be a common yet concerning issue for homeowners. The temperature and pressure relief (TPR) valve is designed as a safety mechanism to prevent your water heater from overheating, but a leak can result in wasted water, energy inefficiency, and costly repairs if not addressed promptly.

There are several reasons why a TPR valve might start leaking, with excessive temperature and pressure within the water heater being the primary cause. It is essential to understand why the valve is leaking and what steps you can take to fix it, ultimately ensuring that your water heater performs optimally and safely.

In this article, we will discuss the potential causes of a leaking water heater pressure relief valve, the steps you can take to identify the underlying issues, and effective ways to address the problem. By gaining a better understanding of your water heater’s TPR valve, you can maintain an efficient and safe household appliance.

Understanding a Water Heater Pressure Relief Valve

A water heater pressure relief valve is a crucial safety component that protects your water heater from excessive temperature and pressure levels. Commonly referred to as a Temperature & Pressure Relief Valve (T&P valve), it is mandated by plumbing codes and ensures proper functioning of your water heater.

The T&P valve is typically located on or near the top of the water heater tank, with a part of the valve extending into the unit. It is designed to release excess pressure and water when the temperature exceeds normal operating limits, usually 150 psi or a specified temperature limit. By doing so, the T&P valve prevents potential damage to the water heater infrastructure or, in extreme cases, catastrophic failure.

There are various reasons why a pressure relief valve might leak. Common causes include a worn-out valve, debris build-up, or high water pressure. It’s essential to identify the root cause of the leak to determine the appropriate solution.

When addressing a leaking T&P valve, the first step should be to check if the valve is worn out or damaged. To do this, turn off the power to the water heater and close the cold-water inlet valve. Carefully lift the valve’s test lever, which should release a burst of water. If there’s no water discharge or the valve continues to leak afterward, it might need to be replaced.

If the valve is in good condition, inspect for debris build-up near or inside the valve. Sediments or mineral deposits can accumulate over time, preventing the valve from closing properly. In this case, the area should be cleaned and flushed, maintaining proper water pressure.

Finally, if the issue persists, high water pressure could be the reason behind the leak. One solution is to install a water pressure regulator in the main water supply line. This device will control the pressure entering your home and prevent it from exceeding the acceptable range for your water heater.

In most cases, a leaking pressure relief valve can be resolved by replacing the valve or making the necessary adjustments. However, if the problem persists, it is advisable to consult a professional plumber for expert assistance.

Common Causes of Pressure Relief Valve Leaks

Excessive Temperature or Pressure

One common cause of leaks in pressure relief valves is excessive temperature or pressure within the water heater tank. When the temperature or pressure inside the tank becomes too high, the pressure relief valve opens to release the excess pressure to prevent the tank from overheating or rupturing. This can lead to a leaking valve, which can occur if the water heater’s thermostat is set too high or if there is an issue with the heating element. To fix this issue, try adjusting your water heater’s thermostat settings and ensure the pressure in the system is within the recommended range 1.

Faulty or Damaged Valve

Another possible reason for a leaking pressure relief valve is a faulty or damaged valve2. Pressure relief valves can wear out over time or become damaged due to various factors, such as corrosion, eventually leading to leaks. In this case, the valve may not close properly after releasing pressure, resulting in a continuous leak. To diagnose this issue, inspect the valve for any visible damage or signs of wear and consider replacing the valve if necessary.

Sediment and Mineral Buildup

Lastly, sediment and mineral buildup can contribute to a leaky pressure relief valve3. Over time, minerals and sediment in your water supply can accumulate inside the tank and on the valve seat, preventing the valve from sealing correctly. This buildup can cause the valve to leak, even when it is not actively releasing pressure. To resolve this issue, perform regular maintenance and flushing of your water heater to remove sediment and minerals from the system and ensure the pressure relief valve can function properly.

Identifying and Diagnosing the Leak

Locating the Pressure Relief Valve

The first step in identifying a water heater leak is locating the pressure relief valve. This valve is typically found on the side or top of the water heater and has a lever handle or a pipe extending from it. To locate the valve, it may be helpful to consult your water heater’s owner’s manual.

Once you’ve located the valve, visually inspect it for signs of leaks. Check for dampness, puddles of water, or mineral buildup around the valve. If you notice any of these, it’s likely that the valve is the source of the leak.

Testing the Valve

Testing the pressure relief valve is an important step in diagnosing the leak. To perform this test, you’ll need a bucket or container, as well as protective gloves and goggles to ensure safety. Place the container under the valve, then carefully lift the lever to let some water out. If the valve is working correctly, a burst of water should release into the container, and then the valve should close tightly when the lever is released.

If the valve does not close properly after releasing the lever, it may need to be replaced. In this case, it’s best to call a licensed plumber to handle the replacement, as water heaters can be dangerous if not properly serviced. Additionally, professional plumbers have the knowledge and experience to diagnose further issues, such as water pressure or thermal expansion concerns, which may be causing the valve to malfunction.

Keep in mind that regular testing of the pressure relief valve is crucial to ensuring the safety and functionality of your water heater. By performing these tests, you’ll be able to quickly identify and address any leaks, ultimately preventing damage to your home and costly repair bills.

How to Fix a Leaking Pressure Relief Valve

Tightening the Valve

In some cases, a leaking pressure relief valve might just need to be tightened. Use a wrench to carefully tighten the valve, ensuring that you do not over-tighten it, as this could damage the valve and worsen the leak. If tightening the valve does not resolve the issue, you may need to move on to other solutions.

Clearing Sediment and Mineral Deposits

Over time, sediment and mineral deposits can build up inside the pressure relief valve, causing it to malfunction. To clear these deposits, first turn off the power and water supply to your water heater. Then, open the valve at the bottom and the pressure relief valve for a minute to drain a little water out of the tank and relieve the pressure. Use a brush or cloth to clean the valve’s interior and remove any build-up. Once finished, close the valve, restore power and water supply, and check for leaks.

Replacing the Valve

If the above solutions do not fix the leak, it may be necessary to replace the pressure relief valve. First, you’ll need to remove the overflow pipe from the pressure relief valve. If it’s been glued or soldered in place, it may have to be cut off. Use a pipe wrench to unscrew the old pressure relief valve.

Before installing the new valve, wrap its threading with teflon tape to create a tight seal. Then, screw in the new valve and tighten it with your wrench. Reconnect the overflow pipe, making sure it is properly aligned with the new valve. Once everything is in place, turn the water and power back on to test for leaks. If the valve replacement has been successful, the leaking should stop.

Leaking Water Heater

Preventing Pressure Relief Valve Leaks

Regular Maintenance

One of the key factors in preventing leaks in your water heater’s pressure relief valve is to perform regular maintenance. Regularly testing the valve and checking for signs of wear, rust, or corrosion can help you address issues before they become problematic. Drain and flush your water heater at least once a year to remove sediment buildup, which can also contribute to valve leaks.

Adjusting the Thermostat

A common cause of pressure relief valve leaks is excessive water heater temperatures. To prevent leaks, make sure your water heater’s thermostat is set at a safe and recommended temperature, typically around 120°F. By adjusting the thermostat, you can maintain a more stable water temperature, reducing the risk of leaks caused by excessive pressure from overheating.

Installing an Expansion Tank

When water is heated, it expands and can cause an increase in pressure within your water heater. Installing an expansion tank can help alleviate this pressure, preventing leaks in the pressure relief valve. The expansion tank absorbs excess pressure, protecting both your water heater and the pressure relief valve from damage due to over-pressurization.

In conclusion, taking care of your water heater by regularly monitoring and maintaining its components can greatly reduce the risk of leaks in the pressure relief valve. By performing regular maintenance, adjusting the thermostat, and installing an expansion tank, you can ensure a longer, more efficient lifespan for your water heater, while minimizing potential safety hazards related to pressure relief valve leaks.

Safety Precautions and When to Contact a Professional

High Water Temperature and Pressure Risks

It is important to be aware of the risks associated with high water temperature and pressure in your water heater. High temperature can cause water to scald individuals, especially children or elderly individuals who have sensitive skin. It is advisable to set your water heater temperature no higher than 120°F (49°C) to avoid scalding risks.

In addition to high water temperature, increased pressure within the tank can lead to leaking from the pressure relief valve. This valve is designed to release excess pressure, protecting the tank from potential damage or explosion. Be cautious around the pressure relief valve, as it may release hot water and steam.

Importance of Timely Repairs

Promptly addressing water heater issues is crucial in preventing further damage and ensuring the safety of your home. A leaking pressure relief valve may be an indication of more significant problems. Potential issues include:

  • Malfunctioning thermostat leading to excessive water temperature
  • Blocked vents or air supply, causing increased pressure
  • Excess sediment build-up, reducing the water heater’s efficiency

Performing regular maintenance checks and addressing any problems in a timely manner will help keep your water heater running efficiently and safely.

When to Seek Professional Help

While some minor issues can be fixed by homeowners, it’s crucial to recognize when to call in a professional. Here are some cases where you should reach out to a professional for assistance:

  • When the pressure relief valve continuously leaks, indicating a possible malfunction
  • If water temperature remains consistently too high (above 120°F), which may suggest a faulty thermostat
  • Presence of unfamiliar noises or smells, which could point to more severe problems within the system

In these situations, a professional will have the expertise and experience to diagnose and fix the issue properly, ensuring your water heater operates safely once again.


A leaking water heater pressure relief valve is a common issue that homeowners may experience at some point. By understanding the main causes and potential solutions, you can confidently address the issue. In many cases, it can be due to mineral buildup or corrosion. A simple fix may be to check the water temperature and adjust it to around 120 degrees Fahrenheit, or “medium” if your thermostat doesn’t have a degree reading.

If the issue persists, you may need to examine the valve itself for any damages or corrosion. Switching off the electric breaker or turning off the water heater gas supply in the case of a manual valve are necessary steps for safety. Once you have safely disabled the water heater, remove the pressure relief valve and examine it closely.

It’s important to remember that a leaking valve can be a sign that it’s working properly and relieving excess pressure in the water heater system. If this is the case, you may prevent future leaks by setting the temperature lower.

While there might not be a one-size-fits-all solution for every case, it’s crucial to be proactive in identifying the cause of a leaking pressure relief valve. Quick action can prevent more serious damage to your water heater or plumbing system. Should you feel uncertain or overwhelmed, don’t hesitate to consult a professional plumber for further guidance.

Frequently Asked Questions

Why is water pouring out of my pressure relief valve?

Water pouring out of your pressure relief valve indicates that the valve is functioning to release excess pressure or temperature from your water heater. This can happen when the water temperature is too high or a malfunction is causing excessive pressure buildup. Ensure the water temperature setting is around 120 degrees F.

Is a leaking pressure relief valve dangerous?

A leaking pressure relief valve can be dangerous if left unattended, as it indicates an issue with your water heater that could lead to further complications. Ignoring a leak could result in water damage or even a catastrophic failure of the water heater, causing flooding or injury. Address the issue promptly to avoid potential hazards.

How can I fix a leaking pressure relief valve?

To fix a leaking pressure relief valve, first, check the water temperature setting and ensure it is around 120 degrees F. If the leak persists, you may need to examine the valve for mineral buildup and signs of corrosion. In some cases, the valve may need to be replaced. Consult a professional plumber if you are unsure about the process.

What are the symptoms of water heater pressure relief valve failure?

Symptoms of water heater pressure relief valve failure can include a constant flow of water from the valve, water dripping or pooling around the water heater, abnormally high water temperatures, or unusual tank noises. If you notice any of these signs, it’s essential to address the issue immediately.

Why does my pressure relief valve leak from the threads?

Leaks from the threads of a pressure relief valve could be due to poor sealing, inadequate tape or compound application, or damage to the threads themselves. To fix a threaded leak, first, turn off the water supply and release the pressure in the system. Then, remove the valve, clean the threads, and reapply the appropriate thread sealant before reinstalling the valve.

How often should a pressure relief valve leak normally?

A pressure relief valve should not leak regularly. It is designed to release excess pressure or temperature only when necessary to protect your water heater from damage or malfunction. If you notice your pressure relief valve leaking consistently, it’s crucial to investigate the issue further and consult with a professional plumber if needed.


author avatar
Anthony Barnes
Anthony Barnes is the founder of Water Heater Hub and a second-generation plumber by profession. Before developing Water Heater Hub, Anthony Barnes was a full-time plumber, and he has undertaken a wide variety of projects over the decades. As a second-generation plumber, it was easy for Anthony to get used to the technicalities of all from a tender age


On Key

Related Posts

Is Drano Bad for Pipes? The Truth Revealed

Note: This post may contain affiliate links. This means that at no cost to you, we may receive a small commission for made purchases. When it comes to dealing with clogged drains, many homeowners turn