Why Your Heater Pressure Relief Valve Is Leaking

Ossiana Tepfenhart
by Ossiana Tepfenhart

Your water heater’s pressure relief valve is there to help keep you safe and reduce the risk of having your heater burst due to excess pressure. When you replaced your valve, you expected it to help keep your boiler safe. Instead, it just started to leak, right after you switched it out. Feeling a little lost, and wondering what gives? You aren’t alone there.

If your valve starts to leak soon after you’ve replaced it, that may just mean that your valve is doing its job. It’s relieving pressure in your heater’s system. In most cases, setting the temperature lower can help. However, you may need to install an expansion tank since your closed water heater system is dealing with an excess amount of pressure.

If you have a leaky T&P (Temperature and Pressure) emergency relief valve, this is a serious issue. If left unchecked, there is a chance that your water heater could explode—literally! This guide will give you a better idea of what you should expect.

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Why Is My Hot Water Pressure Relief Valve Leaking After I Replaced It?

When water is heated, it expands. This increases the force of the water pushing inside of your heater, which in turn, can eventually make your heater pop if left unchecked. A hot water pressure relief valve is meant to get rid of excess water pressure. If the valve is released, excess water will get pushed out of your system.

Most valves leak as a result of cracks from excess pressure, or from long-term use. Replacing a valve helps keep your valve working, but even then, it may leak as a result of excess water pressure building up inside your heater. To put it simply, your valve is making a choice: the leak, or a potential explosion.

How To Fix A New Leaky T&P Relief Valve

With this situation, your valve is actually not the problem. There’s no need to replace it. What you need to address, though, is the pressure in your water heater. Unfortunately, there aren’t many solutions here that can be done on a DIY basis. The below steps can usually help make sure your heater lasts…

Step 1. Start By Checking Your Temperature Settings

The easiest way to decrease the pressure in your water heater is to set the temperature a little bit lower. High temperatures mean more expansion, after all. This fix is relatively easy. All you need to do is check out your temperature setting and lower it slightly. Dry off the area and see if the leak continues. If it does, you may need to look for a different solution.

Step 2. Check The Relief Valve

Believe it or not, there are some situations where the replacement valve might be new, but just stuck or poorly replaced. If your relief valve keeps opening or acting funky, you might want to double-check the workmanship on the replacement. Sometimes, it’s just as simple as not having something screwed on right.

Step 3. Consider Getting An Expansion Tank

Most of the time, the type of water heaters where this occurs can be best described as a closed unit. This is because you have installed a check valve or pressure regulator that releases some pressure but doesn’t let water out. All that expanded water needs somewhere to go while it’s at that high a pressure.

This is why water heaters that have a closed system are typically required to have an expansion tank added onto the unit as part of building codes. If you have a closed system, you may need to get an expansion tank attached to your heater to prevent additional leaks.

Step 4. Check For Excess Sediment

In every water heater, there will be a tendency to gain sediment from poor water filtering over the course of several decades. If you have too much sediment in your heater, this can cause your heater to keep heating up water, even when it shouldn’t. Too much sediment can also cause leaking from the bottom, corrosion, and a slew of other problems.

If you see signs of corrosion or leaking from multiple areas, you may need to replace your heater. Sometimes, flushing out your water heater can help. However, this is not something you should take lightly.

Step 5. It Could Also Be A Thermostat Failure

Let’s say that you turned down the water temperature setting, but things still did not work out the way they should have. The water still is leaking and it actually still feels hot. This could possibly be a sign that your thermostat has gone bad if it’s connected to your water heater or boiler.

When Should You Call A Professional?

A leaky water heater isn’t something you should ever be “casual” about, even if it’s the T&P valve that’s leaking. (Actually, you should probably be especially worried if you see the T&P relief valve leaking!) That’s why it’s often better to be safe than sorry when it comes to this matter.

If you were able to fix the problem by switching the temperature settings to a lower rating or finagling around with the thermostat, then you don’t have to worry. The same could possibly be said if you were able to just work with the new valve and get it unstuck. Of course, these are easy fixes.

If you have reason to believe that your water heater has excess sediment, that you may need a water expansion tank, or if you cannot diagnose the reason why your valve is still leaking, call a professional. Do it sooner rather than later, since this could potentially be a major safety hazard.

How Much Does Professional Water Heater Repair Cost?

If you do call the repairman over this issue, you may have to brace yourself. The average cost for a water heater repair trip can range from $217 to a whopping $935. However, it can be as little as $95 or as much as $1,500…all without replacing your water heater.

In many cases, it makes sense to call a professional who replaced the water heater valve. This is especially true if you notice signs of a bad installation, or if the valve got broken again. They may be able to fix the bad work they did without charging you a dime.

Sadly, a leaky water pressure valve can be indicative of a need to replace your heater. If you need to replace your heater, you’re looking at $1,000 to $3,000 on average, not including installation costs. Be hopeful that this will not be the case in your situation, otherwise you’ll definitely feel pain in your wallet.

Will Homeowners’ Insurance Cover This Repair?

While most homeowners’ insurance policies are very thorough, this is not something you should expect your policy to cover. Generally speaking, home repairs are only covered by your policy if they are needed as a result of damage that has been done due to a peril. A peril is usually something along the lines of a major storm, a fire, or even vandalism.

Wear and tear is not covered by any home insurance policy, no matter how nice it’d be. Unless you can prove, without a shadow of a doubt, that the leaky valve was caused by a peril covered underneath your insurance policy, don’t bother bringing it up to your insurance.

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Related Questions

How common are water heater explosions today?

In the past, a leaky water heater valve was a terrifying sign that turned a typical heater into a ticking time bomb. Nowadays, the threat is still there, though not as bad as it once was. Modern water heaters get equipped with tons of safety features that force a heater shutdown if excess pressure is detected.Believe it or not, thousands of water heater-related accidents happen around the world every year. Even if most of those accidents are not lethal, it’s important to keep your guard up and ensure that your water heater is as safe as possible to use.


What are the most common signs of a water heater that’s about to explode?

A water heater on the verge of exploding will often have a leaky pressure relief valve as the first sign. That often will be followed up with a smell of sulfur, or even a tripped carbon monoxide alarm near the heater. If you hear a tapping, knocking, or groaning sound from your water heater, then watch out! It’s most likely about to blow.If you think that your water heater is on the verge of exploding, turn off access to your water, shut down the heater, and call a plumber immediately. This is a serious threat to your plumbing, your HVAC, and your life.


How long does a leaky water heater last?

If your water heater has started to leak, its time has already passed. Leaky heaters do not last long, though how long they last can vary. Sometimes, it’s only a week or so. Other times, you might be able to stretch it to a month. Regardless of how long they’re technically usable, it’s not a good idea to keep using a bad heater. It’s a health hazard.

Ossiana Tepfenhart
Ossiana Tepfenhart

Ossiana Tepfenhart is an expert writer, focusing on interior design and general home tips. Writing is her life, and it's what she does best. Her interests include art and real estate investments.

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