Water heater leaking from relief valve

Do we even need to state the importance of a water heater?

Similarly, you don’t need us to introduce you to the frustration of a malfunctioning unit, but it’s not just the annoyance that’s concerning. Especially with something like a leaking pressure relief valve, you’re just waiting for disaster to happen!

That’s why we’ve curated this short guide on hot water heater pressure relief valve leaking to give you a heads up on everything you need to know. After going through this brief guide, you’ll know how to detect a relief valve leak, and what to do in case of one.

What Does The Relief Valve Do?

Before talking about anything else, allow us to tell you about the primary function of the relief valve. It’s a crucial safety feature that prevents the water heater from excess heating or pressure-related damages.

If the water temperature inside the unit exceeds 210 degrees Fahrenheit or the pressure build-up measures more than 150 psi, the relief valve goes into operation. The heater will automatically direct the relief valve (also known as the T&P valve) to open and release the extra water till normalcy is restored.

If a recently replaced valve is leaking, that’s probably because it’s doing its job. Here, we should mention that replacing the valve doesn’t take a herculean effort per se. It costs less than $15, and all you have to do is drain some water from the heater, remove the discharge tube and fit the new valve.

How To Detect A Water Heater Pressure Relief Valve Leak?

Given their function, it’s not unusual for users to confuse water heater pressure valve leaking with faulty valves leaking. Hence, homeowners must be able to differentiate between a regular and faulty leak. That’s why we’ve listed some common telling signs that should set the alarm bells ringing:


Even when the valve is functioning normally, water should never be gushing out from the unit. So if you have experienced such instances of pressure relief valve leaking outside, shut off the system and check for the fitting of the valve. If the problem persists, contact a plumber to fix it the right way.

Likewise, the valve shouldn’t be releasing water all the time. If you feel that the valve just never stops leaking, then it may be caused by either frequent overheating of the unit or a defective valve that can’t hold the pressure as well as it should.

Unusual Sounds

Although many water heaters may emit a slight boiling sound, intense rattling or high-pitched whistling noises are primarily caused by the sound of steam trying to escape the tank. This, in turn, may be indicative of excessive pressure against the inner walls of the heater due to inadequate operation by the T&P valve.

Debris Filled Water

Even the smallest piece of debris in the water can be a sign of a corroded tank or heater. If you have cleaned the valve and still observe debris-filled water or a rattling heater, we’d strongly recommend seeking professional help for a thorough evaluation. Remember that running a corroded heater can lead to major accidents sooner rather than later.

Leaking Tank

As you may already know, water leaking from any part of the tank (including the seams) is a definite sign of a ruptured tank. This usually happens when the valve can’t release the water and the subsequent water pressure accumulation goes unchecked for a long time.

How To Troubleshoot A Leaking Valve?

Fortunately, there are a few methods that can be employed to prevent hot water heater relief valve leaking in the first place. In the following sections, we will take you through some of them.

Valve Compatibility

Without a doubt, the first thing that you’d want to keep an eye on is valve compatibility. For instance, if a T&P valve designed for a boiler is accidentally installed on a heater, it will go off at 30 psi instead of 150 psi, and that’s not something you’d want!

Both the temperature and pressure limit for a particular valve will be mentioned on the body or the accompanying tag. So, don’t forget to check the specifications before purchase.

Regular Servicing And Maintenance

In ideal circumstances, the T&P valve should be checked every 6 months for corrosion or any other damage that may hinder the water flow. As such, the valve should last at least 5 years before requiring a replacement. But if you notice one or more of the warning signs that we listed earlier, don’t delay conducting the check.

Temperature Checks

Many homeowners prefer conducting sudden or regular temperature checks to ensure that the pressure relief valve is working correctly. For this, all you need to do is run some hot water through any faucet connected to the heater and take the temperature using a food thermometer. If the valve is leaking at lower water temperatures, it’s probably time to get a new one.

On the other hand, unresponsive valves at water temperatures exceeding the 150 degrees Fahrenheit mark may be a sign of future leaks.

Pressure Checks

Contrary to popular beliefs, testing the water pressure of a heater is a relatively simple process, thanks to the abundance of pressure gauges available on the market. Just attach the gauge to any line connected to the water heater, no matter hot or cold. However, many users prefer to attach it to one of the outdoor faucets.

With no water running in the system, the pressure should read between 40 and 80 psi. Anything more and it may be putting undue pressure on the heater, and subsequently, the valve. You can then choose to install an expansion tank to eliminate the additional water pressure.

Final Words

Hopefully, our efforts have answered all your questions related to T&P valve leaking. Although fixing a leaking valve isn’t a very complicated task, users should not shy away from calling professional help if there is no apparent reason for the leak. If you’re a first-timer, we’d suggest calling in a plumber without any delay.

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