Leaking Water Heater

Leaking Water Heater

Leaking Water Heater

A leaking water heater, even a very small 20-gallon unit, can cause puddles of water in the crawlspace or any part of the foundation, easily noticed in a visual inspection. This water is what animals that burrow under concrete or dig tunnels within the foundation require for living.

That standing water coming from the water heater is also the cause of moisture and will affect the air quality of the entire house, and requires that we remove the water completely and implement some easy preventive measures.

In the US, leaks in the average home waste 10,000 gallons per year. Worse, 10% of US households have plumbing issues so bad they waste 32,850 gallons each year. So, if you’ve noticed your water heater leaking or dripping, it’s best to get to the bottom of the issue ASAP. The sooner you do, the sooner you get to save water, money, and even the water tank itself.

The way the water heater is designed will always make it looks like it’s leaking from the bottom. Since there is housing on top of the insulation, water will stay inside the housing and leak at the bottom. If you verified the water inlet and outlet, t&p valve, and fittings, and everything looks normal, you’ll need to call a plumber to fix that.

The leak may actually be at the top of the water heater and simply running down through the body of the heater before escaping at a lower level.

To confirm if you have a faulty tank (or any other possible leak), conduct a whole-house leak check. You can do this by monitoring your water meter. In many homes, the water meter is outside, on the curb in front of the property. In some, the gauge is in the basement, along the lower section of a wall, and near the floor junction.

Once you find the meter, have everyone at home stop using the water as you run the test. Be sure to completely shut all the taps, toilets, fixtures, and water appliances. Your meter should have stopped moving at this point.

Determination Of The Leaking Water Heater Problem

To determine if it’s your electric or gas water heater leaking, wipe the tank dry first. Then, for your safety, be sure to shut the tank’s power and don protective gloves.

The first spot the plumber will check is the drain valve. This spigot is located at the bottom of the tank and is responsible for draining the sediment from the water heater. If this is the location of the leak, good news, your plumber will quickly be able to replace the drain valve for a relatively inexpensive cost.

Now, if the drain valve is not the source of the issue, you plumber will then inspect the tank itself. If the leak is coming from the bottom of the tank, it is not looking good for you.

The most likely scenario, in this case, is that sediment has built up and corroded the bottom of the tank causing a serious problem and the need for an entirely new water heater.

But there are other possibilities, other places to check

Next, clean the valves as well as the supply lines. Aside from the tank itself, these parts can also develop problems that may lead to leaks.

Once the tank is all clean and dry, pay close attention to its exterior. If moisture develops evenly throughout the surface, then that’s likely condensation.

If you see only the water heater valve leaking, then that’s a surefire sign you have a tank problem. The same goes if water seeps out of a specific spot of the tank or its water supply line.

In some tanks, the damage can be super small that it may take time for the water to seep out. If you don’t see immediate leaks, cover the area right under the tank with some paper towels. Check them for signs of dampness every couple of hours. If the towels do become moist or wet, chances are, you have a water heater leaking problem. If the water heater is leaking from bottom, this is normal since any leak will find is way to the bottom of the tank inside the housing.

Source Of The Problem In A Leaking Water Heater

When we have a leaking water heater, it is crucial that we recognize the source of the problem, which malfunction is causing the issue. Once we acknowledge the “why” it is much easier to know the “how”.

Below all these possible sources for a leaking water heater, I explain how to fix the problem.

Internal Lining Cracks Due to Aging Of The Leaking Water Heater

Just like any other piece of equipment inside your home, water heaters are susceptible to the deteriorating effects of aging. Compared to many of the other appliances you use, though, these water heaters can be quite durable.

They can continuously function with no issue for up to fifteen years, and that’s true even if you barely do anything to maintain them.

Hot water heaters are built with a glass-lined storage tank. Over time, the natural minerals in the water can calcify and create deposits on the inside of the tank. These can crack the glass lining and cause your water heater to leak. Also, as water is heated, it expands. Over time, this expansion creates stress on the glass lining of the heater and can cause it to crack.

So the glass is used inside the water heater as a liner.

Over time, minerals collect and calcify on the glass. This causes the glass to crack and leak water. Additionally, when the water becomes hot it expands, which puts stress on the glass and causes small cracks. Replacements are necessary in both cases. 

The most typical cause of a faulty tank and internal tank leak is a failure to remove sediment from the hot water tank. This is particularly common in areas with very hard water. You should flush your tank and remove sediment every six months.

If you don’t, the efficiency of your water heater will begin to suffer. And over time, the sediment can contribute to corrosion and cracking of the tank shell, leading to a leak that will allow water to pool around the base of the unit.

Unfortunately, when this happens, your hot water heater will need to be replaced; the cracks in the glass liner are not repairable. Sometimes, these leaks will not affect the performance or function of the unit and the people elect to wait to replace the water heater. As long as the leaking water isn’t causing damage, this is fine, but ultimately the unit will need to be replaced.

In the case of internal damage to the hot water heater, you’ll almost always need to replace the unit completely. If you think that your hot water tank is compromised but you’re not certain, it’s a good idea to hire a plumber to take a look at it – that way, if the issue isn’t with the heater tank, you can avoid the expense of purchasing a brand-new unit.

Tank style water heaters older than about 15 years leak more often than newer heaters. As the unit ages, the parts wear out, the water doesn’t keep its warmth as well, and leaks occur more frequently. Water heater leaks due to old age sometimes happen because rust forms in the tank. This leads to corrosion, which allows water to exit through cracks. When the water heater reaches the end of its life, the only thing to do is replace it.

We have an article about water heater disposal where I explain to you that you can earn some money from your old water heater during the disposal process.

Sediment Built In The Tank Due To Lack Of Maintenance

Even when the weather heater is within its lifecycle, and still not to be disposed can accumulate particles of sediments because it was not properly maintained.

As water heaters age, they collect sediment at the bottom of the tank. Homeowners who regularly clean the water out of the tank rarely experience this issue. However, for those who forgo draining the tank to clean it, sediment builds until cracks form. These cracks allow water to leak through. Tank leaks require an entirely new water heater which are expensive, so make sure to clean the tank semi-regularly.

Water heaters that are not cleaned out periodically can build up sediment in the tank. Salt and other chemicals in the sediment may lead to premature rusting or corrosion inside of a water heater and eventually cause pinhole leaks to form.

Once a pinhole leak is opened up, the pressure of the water inside the tank forcing its way through the opening will cause the leak to get larger over time.

I’ve heard cases where a leak in an inside closet allowed a stead source of water under the crawl space. Next thing the homeowner knew, they were trying to get rid of a family of chipmunks living under their home.

The best solution for this problem is to replace the tank with a new unit. A leaking tank is an obvious sign of a water heater needing to be replaced.

Normally, replacing a water heater should be done by a professional but if you’re a DIYer, you can do it yourself. On most models, you will need to remove the plumbing connected to the water heater, and disconnect the power inside the access panel. For gas water heaters, be sure to turn off the gas line leading to the water heater, and disconnect the line where it enters the tank.

Replace the water heater with a new unit and reconnect the pipes and power. “How long do water heaters last?” is question usually related to the water heater tank itself. When the tank is damaged, it’s time for a new unit.

Anode Rod Requires To Be Replaced

An anode rod acts as a sacrificial component of the water heater. It attracts corrosive substances so the water heater itself stays safe. However, water heater leaks occur when the anode rod becomes nearly nonexistent because of all the corrosion. Water leaks through the space where the anode rod used to be. Quick replacement takes care of any potential leaks.

Cold Water Inlet And Hot Water Outlet Connections As The Cause Of A Leaking Water Heater

Cold water enters through the inlet connection, and hot water leaves through the outlet connection in a water heater. These connections allow hot water to enter your water fixtures. Over time, these loosen and cause leaks. It’s rare for any other issue to occur with the inlet and outlet connection.

If your water heater has a pool of water on top, there’s a good chance that the source of the leak is either the incoming water supply valve, cold water inlet, or the hot water outlet.

If you have a leak coming from the area where the cold water inlet or hot water outlet connects to the water heater, you may be able to fix it by tightening the connections with a pipe wrench.

If tightening the connectors doesn’t stop the leak, then you should replace the flex lines that supply the cold water (or hot water).

Whenever there are pipe connections, there’s a higher chance of a leak. Follow the cold and hot water pipes. Do you see any water? Are the fittings tight? Is there any leakage around the shutoff valve on the cold water supply line?

Because of where they are on the water heater, the hot and cold inlets and outlets are more susceptible to damage compared to its other components. Check on these if you’ve noticed that your heater is starting to leak.

If this area is the source of your leak, it is a very easy fix. Simply check the inlet and outlet pipe’s connections and see if they are loose and causing water to leak. If this is the case, you may just need to tighten the connection with a wrench or replace a faulty pipeline.

Failure In The T&P Relief Valve Related To The Excess Of Pressure

Water heater leaks also occur because of the temperature and pressure relief valve, known as the T&P valve.

When pressure builds within the tank to an unsafe level, the T&P valve relieves the tank pressure by opening the valve and allowing some of the water out of the tank.

This will prevent the tank from bursting or exploding!

So what does this mean:

If there is too much pressure in the tank, or the water becomes too hot, this valve will drain some of the water out of the tank.  If this T/P valve is the source of your leak, you will most likely be able to see water running down the side of your tank from the valve.

You can find the T&P relief valve on the top of your water heater or on the side. Look for a copper or PVC pipe that runs down the side of the tank towards the floor. This is the T&P drain pipe and it connects to the relief valve.

If this is the case, it could mean you need a new valve because the one you currently have is broken, or, it could also mean it is working properly and there is too much pressure in your water tank, so it is forcing water out through the T/P valve to prevent a bigger problem from occurring.

This valve helps relieve pressure inside the tank. When this valve doesn’t work, the pressure in the tank increases. Sometimes, the valve is simply loose and requires tightening. However, if the part is faulty, the piece needs a replacement. 

The T&P (Temperature & Pressure) relief valve is a safety feature found on all commonly-sold hot water heaters. It releases excess pressure from the tank through a tube directed at the floor – if the pressure gets too high in the tank, water will typically be sprayed through this tube as the pressure is relieved.

The T&P valve is an important safety measure for your water heater to relieve excess pressure if the water heater gets too hot. On most water heaters, the pressure relief valve is on top of the unit, but most systems include a tube attached to the valve in order to channel the water to the floor.

When the T&P valve is leaking, it may appear the issue is at the bottom of the tank since the overflow tube discards the expelled water underneath it. Since the T&P valve is designed to allow water to be released from the tank, the first thing to do is check the thermostat setting to make sure that it is not turned up too high.

If you check your discharge tube and it’s wet, the T&P valve is probably the culprit. It may be faulty, and activating even when the pressure inside the hot water tank is normal. You’ll need to call a plumber to replace the valve and ensure your tank stops leaking.

Lower the pressure in the tank before you deal with T&P valve issues.

If the valve deals with too much pressure, it could start malfunctioning. The problem could also stem from the water heater raising the water’s temperature excessively. That can lead to damage to the temperature and pressure relief valve.

Sometimes a water heater tank can build up too much pressure which can cause leaks. This can happen with the water temperature is set too high or the exterior water supply is coming in at too high of a pressure for the tank.

In rare cases, though, your T&P valve may be functioning properly – and there may be too much pressure in your hot water tank. Pressure may build if the hot water tank is heating water too high (exceeding 140-145° F), which could happen with a faulty temperature regulator. Your hot water heater may be at risk of bursting if it exceeds its rated PSI, so contact a plumber for help immediately.

Step by Step Approach To Investigate If The T&P Valve Is The Source Of The Leaking Water Heater

  • Check the area where the T&P relief valve enters the tank for signs of a leak.
  • If the T&P relief valve is in the closed position and water is flowing from the attached pipe, the valve is defective and needs to be replaced.
  • If the T&P relief valve is in the open position, it may be relieving excessive pressure from the tank (which is forcing the valve open). If this is the case, the leak is generally fixable, but the situation should be taken very seriously. We highly recommend calling a professional plumber.

Since the T&P relief valve is a safety device, and if this is the source of your leak, it’s important that the valve is either replaced, or a plumber is called as soon as possible.

A T&P relief valve issue does not necessarily mean you’ll need to purchase a new water heater, but the leak does need to be addressed. 

Troubleshooting The Temperature And Pressure (T&P) Relief Valve

In the previous approach we have discovered that the issue of the leaking water heater is in the T&P valve and there could be several rationales for this:

  • Faulty valve
  • Clogged valve
  • Excessive PSI and/or water temperature within the tank

Since the T&P relief valve is designed to prevent your water heater from overheating and developing excessive pressure within the tank, it’s a good idea to do a little extra troubleshooting before assuming the valve is faulty and simply replacing it with a new one.

It’s also not uncommon to notice water leaking from the threads of your T&P relief valve where it attaches to the tank. If this is the case, you’ll need to remove the T&P valve and check the tank for signs of rust or corrosion.

If you see signs of rust or corrosion it’s an indication that the problem is with the internal tank. Unfortunately, you’ll need to purchase a new water heater.

However, if the tank appears to be in good condition, you can wrap the threads of the T&P valve with Teflon tape and screw it back into the tank. It may simply not have had a good seal.

Keep an eye on your water heater for the next few days to see if this resolved the leaking problem.

Material Fatigue In The Drain Valve Causing A Leaking Water Heater

Another common cause of water heaters leaking from the bottom is a drain valve that’s not completely closed or is faulty and is leaking.

The drain valve is used to drain out the tank to perform maintenance or repairs on the water heater, and is also used to drain sediment that gathers at the bottom of the tank.

Corrosion, rust, and temperature variations, affect the stress quantity that the drain valve can withstand. Therefore, we speak about the material fatigue of the drain valve as a typical cause of a leaking water heater device. If this watertight drain valve is what provoked a leaking water heater, replace it because it is very cheap.

So we go to the bottom of the water heater tank and we encounter there the drain valve. Its goal is the drainage of the tank when it is required to repair the leaking water heater device or for simple maintenance.

This valve loosens over time, which allows water to leak through. However, leaks from the base of the valve indicate that the component isn’t watertight. In this case, a new drain valve is necessary.

All water heaters have a drain near the bottom of the unit so that the tank can be emptied before removal, or during routine cleaning of the tank itself. A leaking drain valve can be identified by moisture or water dripping, either out of the drain opening or around the valve itself.

Check to make sure that the bottom valve is fully closed by turning the valve control clockwise. If this does not solve the problem, the valve may need to be replaced.

To replace the valve, you will need to connect an ordinary water hose between the drain outlet and an outside location. Next, turn off the water inlet for the tank, usually located at the top of the water heater on the cold water line. Open the drain valve and allow the tank to empty.

Replacement valves for hot water heaters are available at most hardware stores, and can be replaced with only a wrench. Turn the existing valve counter-clockwise to remove it.

Wrap the threads of the replacement drain valve with plumber’s (Teflon) tape or joint compound, and then screw the new valve into the opening until it is hand tight. Using a wrench, tighten the drain valve 1/2 turn, or until the drain is tightly in place.

Since they designed the drain valve to get rid of any sediment that makes its way into the water heater, you should expect it to drip at least a little. However, there’s a significant difference between regular dripping and a full-blown leak. Make sure that the drain valve is not releasing any more than it should because that could grow into a real problem sooner rather than later.

It water appears to be leaking from the valve, try tightening it with a wrench until it is snug, but be careful not to over-tighten it.

If your drain valve is leaking, it may not be damaged. It’s possible that it’s just not completely closed. You may have knocked the handle loose at some point, loosening the drain valve slightly and allowing some water to drip out. Check the knob or handle and ensure it’s completely tightened.

If the water stops dripping, congratulations! Your water heater is in good shape. But if the leak continues, the valve itself is faulty and will need to be replaced either by you (if you’re handy) or by a plumber. The leak will only get worse with time, so we recommend handling the issue as soon as you can.

Step by Step Approach To Investigate If The Drain Valve Is The Source Of The Leaking Water Heater

  • Verify that the drain valve is completely closed.
  • If the drain valve is closed, and there’s moisture coming from the drain opening, then the valve may be faulty and will need to be replaced. 
  • Check the area around the drain valve where it enters the tank. There should be no signs of moisture. If you do have moisture where the drain valve enters the tank, it’s likely that you have an internal tank leak. 

Troubleshooting The Drain Valve: Is The Issue Actually In The Drain Valve?

If your water heater is leaking from the drain valve, it is generally one of two things:

  • There is debris inside the valve preventing it from fully closing
  • The drain valve is faulty

First we need to rule out that a clog is preventing the drain valve from closing. Here’s what to do:

  • Place a bucket under the valve and turn the dial counter-clockwise. If there’s not enough space between the floor and the drain valve for a bucket, you may need to attach a garden hose.
  •  Once the drain valve is open it should flush out debrisIf it’s been awhile since you’ve flushed your water heater tank, it’s possible that your drain valve will clog. 
  • Allow the water to flow through the valve until it runs clear. Then close the drain valve.

Replacement Of The Drain Valve To Solve The Leaking Water Heater Problems

If after all these troubleshooting, you still have a leaking water heater, then the drain valve requires a replacement.

Changing a drain valve is relatively easy, and something you can do yourself once you buy a new valve. Always be sure to purchase one that’s compatible with your water heater.

In order to replace a drain valve, you’ll need to drain the tank. Be careful not to come in contact with the hot water.

Water heaters are usually factory-set to heat water to 125°F, which is hot enough to inflict first degree burns to skin on contact. And, if the water temperature was set to maximum, the water could be anywhere from 160° to 190°F which could result in serious injuries!

Defects In The Insulation Layer Of The Internal Shell

Tank water heaters use two shells to complete its processes. The external shell provides insulation for the internal shell which holds the water. A final layer of metal covers both shells. Water heater leaks in the internal shell are difficult to spot, but occur because of age and deterioration in most cases. You don’t see this type of leak from the outside of the tank. 

Water heaters have a steel internal tank which is wrapped in insulation and then enclosed within an outer visible skin.

If the internal steel water tank is leaking, you won’t be able to see it by looking at the outer skin. In most cases, you’ll notice water under the water heater since the most likely way for it to escape is from the bottom.

When you were inspecting your drain valve and T&P relief valve, you may have noticed moisture where the valves entered the tank. If this was the case, there’s a good chance that your internal water tank is leaking.

So even with a proper maintenance, water heaters have a limited lifecycle. Glass lining that cracks, an insulation layer broken within the internal shell, all very typical of an old water heater.

Howver, when you dispose the extinct old leaking water heater, you still can collect a few dollars through recycling, and I explain you how in its article.


Condensation is not always an issue and is normally not the cause of a leaking water heater. Nevertheless, allow me to distinguish in these paragraph the different ways in which condensation may appear.

First of all, determine if the water you’re seeing is condensation or an actual leak. Homeowners sometimes worry over nothing, so it’s good to double check before you call a plumber. Condensation occurs when the temperature in the room varies wildly from the tank. For example, if the tank is very hot, but the room is cold, condensation occurs. Condensation doesn’t indicate any problems with the water heater.

Some water heaters may experience condensation on the water tank. This more common on older water heaters, but it can happen to newer tanks if the insulation has been damaged or the thermostat is set too high for safe operation. Allow the tank to sit idle for several hours with the power or gas turned off.

If the leak stops, it is an indication that you are experiencing condensation. Turn down the thermostat and restore power to the unit.

If the problem persists, you may need to replace the tank with a better insulated model. See our list of recommended water heaters to see just how well insulated current models have become.

Condensation may also occur temporarily after a new water heater is installed and the cold water that fills up the tank hasn’t had a chance to heat up yet. The temperature difference between the inside of the tank and the outside air oftentimes causes condensation.

Water Pressure Typical Of Any Plumbing Fixture

Like any plumbing fixture, water heaters deal with naturally occurring water pressure. Pressure occurs in water heaters because the hot water creates steam and fills the empty space. When this steam has nowhere to go, the pressure becomes too much. Water leaks through any crack in the heater to relieve some of the pressure. When the water temperature is set too high, or if water enters the system at high pressures, the heater pressure increases.

The Telltale Signs That Your Water Heater Is About to Leak

Unless your tank has a big hole in it, chances are you won’t notice there’s a leak right away. Inspecting your water heater now and then is a wise move, but the vast majority of homeowners don’t do that often enough.

The good news is that you don’t need to perform a thorough inspection of your water heater regularly to find out that it’s broken. You can keep an eye out for some of the symptoms of a broken water heater that we note below.

The Water Quality Has Changed

A lot of people prefer taking hot water showers in the morning. Some are capable of tolerating freezing cold water hitting their body that early, but others cannot handle it.

Now, you don’t necessarily need to worry about cold water raining down on you if your water heater is leaking, but you may notice that the water coming out is lukewarm instead of hot.

There’s a tendency to shrug off this anomaly and think of it as a byproduct of a colder than usual morning, but it could be an indicator that your water heater isn’t working correctly.

You can also get a hint of how well your heater is working by checking out if the water has rust particles in it. This is an issue you may have detected already because some of the clothes you’re washing suddenly have rust marks on them.

To check if there is rust in the water, you can pour some into a clear glass and see how the liquid looks. While you shouldn’t do it intentionally, you may also notice the rusty water while showering as some droplets get near your face due to the unusual smell and taste.

Rusty water is a sign that rust is starting to accumulate inside your water heater. It may not be leaking yet, but it could happen shortly.

The Exterior of the Water Heater Looks Rusty

Speaking of rust, you don’t need to detect it in the water to know that your heater could have problems sometime in the near future. You can also take a look at the exterior heater and see if rust has started to accumulate on it.

Rust showing up on the tank is a pretty good sign that there is a leak somewhere. Take the time to look at the burner units, too; they are similarly prone to rust.

The Water Heater Is Producing Noticeable Noise

Sediment piling up inside the water heater is inevitable. For a long time, that sediment will not make its presence known. Eventually, though, the sediment will harden and start to cause some noise whenever the water heater is in action.

If you’re trying to figure out if there’s something wrong with the heater, listening to it could work.

Puddles of Water Are Forming around the Water Heater

This is an obvious thing, but yes, if you’re starting to notice there are puddles of water forming around the heater, you should take that as a sign there’s a leak.

More often than not, the puddle of water indicating the leak will be directly under the heater.

Location Of The Origin Of The Leak

Even if you can see some puddles of water near the device, we cannot yet establish that there is a leaking water heater or that the stagnant water comes for the many reasons that we describe in this article.

So let´s investigate all the possibilities.

Even if you already know that the water heater is leaking, it’s important to remember that you cannot fix all leaks the same way.  As we noted above, the leak could be due to faulty connections, valves, or even the tank itself.

Undefined Location

Water heater leaks sometimes seem to appear out of nowhere. In these cases, you likely notice pools of water under the unit. Too much pressure is the most likely cause. When pressure leaks occur, the water finds any tiny crack to leak through, then the leak stops when the pressure goes down. This makes it hard to locate the source unless you catch the leak as it happens.  

Bottom Leaking Water Heater

Either the drain valve or the tank itself causes these water heater leaks. Drain valves usually need tightening, but if the tank has a leak, the whole thing needs to go. These replacements are expensive, but necessary.

Top Leaking Water Heater

When water leaks from the top of the tank, the inlet and outlet connections are usually to blame. It’s rare for tank cracks to occur on the top, but it is possible. Other causes include loose T&P valves and anode rod corrosion. Luckily, repairs, replacements, or tightening the components are usually the most homeowners must do to resolve this type of leak. Only a crack results in a new water heater.

Internal Leaks

Finally, water heater leaks inside the tank are impossible to see on the outside. While the water often pools at the bottom of the unit, this doesn’t mean the leak stems from there. The crack on the internal tank could be anywhere. Age and deterioration are the leading causes of this leak.

Visual Inspection To Valves

As for the valves, nothing beats a close inspection to see if they are all sealed or causing water to drip out.

Leaking Is In The Piping Network And Not In The Water Heater

Check your surroundings for other possible sources of water. Is the water found near a window or another water pipe? Keeping gravity in mind, if your floor slopes at all, water may have traveled from another area to where you found it.

If you can’t determine the cause right away, put down some paper towels where you found the water and check back in a few hours to a day or two.

When you come back, If the towels are wet, then you know there is a problem and the water heater may be the culprit.

How to Fix a Broken Water Heater

You now recognize the symptoms and can determine your water heater is leaking. So, what should you do next?

Here are some tips for how you should go about addressing the problem of your leaking water heater.

Turn Off the Water Supply Valve

If you experience a leaking water heater, it is recommended to turn off the water to your tank.

Once you’ve confirmed that your tank does leak, the next step is to close its shut-off valve (shut off the water). This stops more cold water from flowing into the tank. If you had to switch the heater back on, be sure to turn off the power again before working on the shut-off valve.

On top of your water heater there should be two pipes. One will be warm to the touch and the other cold. Some manufacturers even identify them with red and blue collars or paint.

The pipe that’s cold is the water supply line. It allows cold water to enter your water heater when hot water is drawn. Follow the line and look for a shutoff valve. Most water heaters have a shutoff valve on the water supply line.

Your water heater tank should have a dedicated shutoff valve on the cold inlet pipes.

  • If this is a gate-style valve (a wheel that turns), turn the valve clockwise as far as you can. They are also known as dial valves. So you have to turn this wheel clockwise until it cannot be turfned anymore.
  • If the valve is a ball-style valve, turn the handle 180 degrees. Ball valves have a lever type handle. Pull or turn the handle down to shut off the water supply.

If the valve is broken, you can shut the water off to your home. Each home should have a main water shut off valve that would stop the flow of water to the entire house.

In most tanks, the shut-off valve is right above the water heater, installed on the cold water supply line. This may either be a gate valve that you need to turn or rotate or a handle that you can easily pull down.

If you are helpless to discover this shut-off valve, please complete the form below and you can schedule a time to have several quotations to compare and a service technician can visit you and help you urgently.

Case Of A Water Heater Without Shut-Off Valve

Although the majority of water heaters have a shutoff valve on their water supply line, some do not.

In this case, you may need to turn the water off using your home’s main shut-off valve. This will shut down all the incoming water to your house, including the water supply to your water heater.


You should shut electric water heaters down by using the circuit breaker box. Find the breaker that goes to your water and shut it off. You need to be thorough because you never want to be in a position where you could be standing in water while some electricity is still flowing through the wiring.

Gas heaters are easier to turn off because flicking the switch will do.

Drainage Of The Tank

Once you’ve managed to completely shut down the water heater, you can proceed to drain the tank. Use either a hose or container to catch the water to keep your basement floor from turning into a riverbed.

Your water heater technician will drain your tank when they begin work.
However, if your tank is leaking badly, you may want to drain it immediately to prevent water damage.

If you need to drain your water heater before a technician arrives, follow these steps once the water and power have been turned off:

  1. Hook a garden hose to the drain valve at the bottom of the tank and run it outside on the ground. Make sure you drain the tank to a proper location such as a gutter drain or sink. Do not drain the water onto your lawn or driveway as sediment and rust from the tank can harm your grass or stain your driveway.
  2. Open the drain valve where the hose is attached.
  3. Open the pressure relief valve on top of the tank by pulling up on it.
  4. Allow the water in the tank to drain out.

Again, unless you are worried about severe damage, you don’t have to worry about draining your water heater. Technicians will be happy to take care of this for you.  

Taking these first few steps when you discover a leak can be instrumental in avoiding water damage.

Closing Off the Water Supply After The Drainage Of The Tank

With the tank now empty, you can get to work on closing the water supply.

Look for the cold water shut off valve first. As long as you’re certain you can reach that valve safely, you can turn it off yourself. Doing that should be enough to prevent more water from pouring into the heater.

If the heater’s cold water shut off valve is located in a difficult spot, you can target your home’s main water valve instead.

Turning Off The Power Supply

Follow the steps below for either an electric or a gas water heater.

Electric Water Heater

If you have an electric water heater and are experiencing difficulty, we recommend that you shut off the power at the breaker before working with the tank. Just flip the breaker to off.

So these are the steps to follow

  • Locate the breaker to your water heater in the household electrical panel. It will be on a dedicated circuit breaker.
  • Flip the breaker to OFF.

Gas Water Heater

If you have a leaking gas-powered water heater, we recommend that you shut off the gas supply before working with the tank. There should be a dedicated gas shut off valve on the gas line leading to the tank.

  • Locate the valve on the gas supply line. The line is usually within a couple feet of your water heater. It’s located near the bottom and connects to the gas control valve.  
  • Turn the valve on the gas supply line clockwise until it stops. This will shut off the gas supply to the water heater.

Once your water and power have been turned off, you can better assess the situation and determine where exactly the leak may be coming from.


  • Check the inlet and outlet.
    Where pipes connect to your water heater are often sources of leaks. Check the cold water intake and hot water output connections.
    Are any of the fittings lose? They may just need to be tightened with a pipe wrench.
  • Check the pressure relief valve.
    The pressure relief valve, also called the T&P valve, may release water as a safety measure if too much pressure builds up. If your temperature is set too high, or if the water pressure to your home is excessive, pressure can build up causing leaks at the valve.
  • Check the thermostat settings to make sure the temperature is not turned up too high. (and you can check the pressure of your home using a pressure gauge at a hose bib) What temperature should your water heater be set to? Most manufacturers have a default setting of 140 degrees Fahrenheit, however, the Department of Energy recommends setting your tank-based water heater to 120 degrees Fahrenheit. If you are seeing water leaking from the T&P valve, either it’s doing its job by expelling water when the pressure builds up, or the valve itself is faulty. If your temperature is not set too high and you are still seeing leakage, the problem may be with the valve itself.
  • Check your water pressure.
    It’s also a good idea to check the pressure as well as the temperature. You can check the pressure by using a pressure gauge at the hose bib outside your house.
    What if my inbound pressure is too high? Your inbound water pressure should not be over 80 PSI per code,  and if the pressure is over 100 PSI, we strongly recommend you put in a pressure reducing valve. Your water pressure may not only be causing a leak, but it may also be causing damage to your fixtures.
  • Check the bottom of the water heater.
    Sometimes it can be difficult to determine the source of a leak, especially if water is collecting below the tank itself. Water leaking from a valve may run down the sides of the tank giving you the impression that the leak is coming from the bottom, but it’s really originating from the top or sides. If the leak is coming from the bottom of the tank, the tank itself may be cracked, which means it will need to be replaced.
  • Check the drain valve.
    Located towards the bottom of the tank, the drain valve should be closed completely, so make sure there is nothing leaking from this point. If it is leaking, the washer inside may be worn and need replacing.If you still can’t determine where the leak is coming from, give us a call and one of our technicians will be able to assist you.


Leaking Water Connections

The two pipes connected to your tank top are the cold water inlet and hot water outlet. Since water continuously flows in and out of these lines, they can become loose or detached over time. If this is where your water heater leaks from, then you may only have to fasten the loose connections.

A pipe wrench should do the trick. But, again, be sure that your water heater doesn’t have power before you secure the connections. This is especially important if it’s the hot water outlet that you need to deal with.

A Leaking Drain Valve

The valve near the bottom of your water heater tank is the “drain valve.” This is the component that lets you drain your tank for maintenance purposes. Speaking of which, you should flush and clean your tank at least once a year to get rid of sediment buildup.

Like all other connections, the drain valve can also become loose over time. If you’ve seen your water heater leaking from this part, tighten it slightly with a pipe wrench. Be sure to do this slowly to avoid overtightening the valve, which can lead to the leak getting worse.

If the water heater is still leaking, you may need to replace the entire drain valve. This is a more complex job, so it might be best to leave it in the hands of a professional plumber.

A Leaking Temperature & Pressure Relief Valve

Your water heater comes with a temperature and pressure relief valve. It’s a device that lets steam or water exit the tank to avoid a buildup of excessive temperature or pressure. It should do its job if the temperature inside the tank exceeds 210 degrees or if the pressure goes beyond 150 psi.

Because it’s a valve, this component of your water heater is also susceptible to leaks. One way that this can happen if it gets stuck in a partially-open position. If it becomes defective, it may allow water to flow out of the pipe it connects to.

In this case, your best and safest bet is to ring up a plumber. After all, you’re dealing not only with leaks but also temperature and pressure. A slight mistake can cause severe health and safety hazards.

A Leaking Tank

Insulative materials cover the internal tank of a water heater. An outer skin then wraps around this entire part. If the inner part starts to leak, the most common symptom would be a leak that escapes from the bottom of the tank.

If this is the root cause of your water heater woes, then you’d need to replace the water heater. Unfortunately, these leaks are often non-repairable, as they’re usually a sign of deterioration.


It’s now time for the actual repairs, and they can range from being rather simple to remarkably complicated.

If the issue is related to cold and hot water inlets and outlets, you could resolve the problem yourself.

Check out the connections and see if there are any spots where they are loose. Bust out your wrench and tighten them. Doing that should be enough to get rid of your leaking issue.

Things won’t be quite as easy if the issues plaguing your water heater are related to the valves. There may be something off with the water pressure, but the issue could also be a broken valve.

In that case, you will need to replace the valve.

You could try to do that yourself, but if you lack the experience, you may end up making things worse. This is the point where you should strongly consider reaching out to the skilled and experienced professionals who handle these repairs all the time.

Lastly, if the tank itself already has a sizable hole in it, repairs may no longer work. You may need to invest in a replacement water heater at that point.

Preventive Maintenance To Avoid A Leaking Water Heater In The Future: Always Act Quickly

The most important part of leak identification deals with reaction time. The faster homeowners identify a leak, the less likely they are to experience extreme water damage. However, with preventative measures, homeowners don’t experience leaks in the first place. Here’s how to keep your home safe from leaks.

Quick responses to any water heater leaks ensure homeowners don’t face harsh repercussions. If leaks run for long periods of time, floods are more likely to occur. Plus, when pressure builds in the tank for too long with no relief, the heater has the potential to explode. Quickly attend to leaks to ensure these scenarios don’t happen.

Install a Powered Anode Rod to Prevent Water Heater Leaking

One thing you should always do is to keep an eye on the anode or sacrificial rod. This component of the water heater is responsible for gathering any debris inside the tank. Check on that semi-regularly to see if it still works properly.

You will probably need to replace it after two to three years.

If you had a water heater leaking because of corrosion or you don’t want that to happen, we suggest installing a powered anode rod. This anode uses current to protect against corrosion and Reduce Limescale buildup inside the tank.

Replace the Magnesium Anode Rod Before It Completely Corrodes

Inside your water tank is a sacrificial part called “sacrificial anode rod.” In any case, an anode rod sacrifices itself to protect the interior of a water heater tank. It attracts elements in the water that can corrode and destroy the other metal parts of the tank. You can think of the anode rod as a magnet. It draws in minerals and metal ions that can otherwise cause oxidation and rust in the heater.

If you don’t install a powered anode rod or never change your magnesium rod, you will have a water heater leaking in your home after only a couple of years.

Sacrificial magnesium anode rod is hard to install and doesn’t last long (only last 2 or 3 years). They are called sacrificial because they sacrifice themselves to protect the tank. Because of its purpose, an anode rod has a shorter life than the entire tank. This is also why you need to replace the anode rod before it gets completely eroded.

Consider a Water Softener

Hard water isn’t usually a health threat, but it can cut the life of your water heater short. It can also reduce the efficiency and the performance of your heating system.

A study found that hard water makes water heaters use more energy than those that heat soft water. The researchers also noted that households with soft water buy fewer cleaning products. That’s because soft water is easier to clean with than hard water.

Another study found that long-term exposure to hard water can cause damage to pipes. The dissolved minerals in hard water can cause limescale formation in the pipes. Over time, the hardened minerals can corrode pipe components. If that happens, you should see some hard water stains in all your faucet.

If you live somewhere where the water is hard, consider using a powered anode. This will help your water heater last longer and become more energy-efficient. A powered anode rod is your best bet since this lasts longer than traditional rods.

Flush The Tank Once A Year To Avoid A Leaking Water Heater

A clean water heater tank is less likely to crack due to sediment collection. Homeowners are able to clean the tank themselves. Use the drain valve to empty the water, then use a bleach-water solution to clear away any mold and mildew growth. Not only does this improve the water quality, it also ensures sediment collection doesn’t damage the tank. 

Flushing the water tank of the heater is also something you should do if you want to prolong the life of this appliance. The process of flushing the tank is simple enough. Do it once per year to keep your water heater in good shape.

Tighten With A Wrench All Loose Parts

Make sure to check how tight all of the component are on the water heater. Loose parts allow water to leak through, so tighten them as often as necessary. All you need is a wrench. 

General Water Heater Preventive Maintenance

If you don’t want to deal with a water heater leaking in the future, make sure you are doing a proper maintenance. Aside from flushing your tank and change the anode once a year, be sure to give all its parts a thorough cleaning too. Wipe your tank’s exterior as well as its valves and water connections. This way, you can get rid of dust and debris build-up, which can contribute to reduced performance.

Regular maintenance done by a plumber ensures the water heater doesn’t experience any leaks. Maintenance checks allow plumbers to inspect the entire plumbing system, which means they cover the water heater. They make sure there are no active leaks, and they take a close look at all the components to see if they have the potential to cause leaks in the near future.

Replacement Of A Leaking Water Heater With A New Unit

As we discussed above, when you find water under a water heater the problem can be serious and action should be taken as quickly as possible.

Depending on the type of leak, you’ll either need to repair or replace your water heater. Although, many of the repair fixes can be performed by the homeowner, frequently people prefer to call a professional plumber.

Your comfort level in tackling DIY projects will likely be the determining factor.

Water heaters generally last 8 to 12 years. So if your leaking water heater is nearing old age, you may choose to replace it with a new energy efficient model rather than pay for repairs.

New water heaters are far more energy efficient, which means they will save you money each month in operating costs. They’ll also be under warranty, so any issues for the next couple of years will be covered.

We recommend considering the cost of repairs and the age of your water heater when you make your decision on whether to repair or replace your water heater.

Water Heater Disposal

If you hire a plumber to replace your water heater, in most cases they’ll get rid of the old one for you. However, if you’re replacing the water heater yourself, you’ll need to find a way to get rid of it on your own.

We have an article for replacing the old water heater. You can recycle it and even get some money from it. Read the water heater disposal article here.

Dangers Of Having A Leaking Water Heater

In most cases, it is not dangerous to have a leaking water heater, unless the issue discovered is because of a malfunction detected in the T&P valve. In this case it can become dangerous.

Your water heater is malfunctioning and causing either the internal tank pressure to be above 150 psi or the water temperature to be above 210°F. Turn off the power and call a professional immediately.

However, in most cases, water damage is the biggest concern. Repairing damaged floors can be expensive and it’ll be critical that the clean-up is properly done or you may develop mold and mildew. Mold and mildew can be a health hazard and can cause serious respiratory problems.

Recommended Articles

We have some articles that I would like to recommend to the readers.

Foundation Repair And Maintenance

We have described here the type of foundations, what is a foundation inspection and what should be included in a good foundation inspection checklist. We can discover problems in the foundation to make us ask ourselves if it is safe to live in a house with foundation problems, and what entails a foundation repair. Not only the repair activity itself but how it affects our wallets.

I explain if the foundation repair is actually covered by homeowners insurance and the actual foundation repair cost. We disaggregated these foundation repair costs and determined, the cost per pier when footings or piers are the solutions for the settlement of a foundation.

To repair a foundation, the service provider might require an underpinning system using piers: push piers vs helical piers where helical piers are preferable for residential real estate objects, despite their costs. Also when you compare helical piers with concrete footings, we can determine that helical piers are more cost-efficient than concrete footings, in my opinion.

We have water in the crawlspace, which can be an issue for the whole foundation if the problem persists, and an additional difficulty when selling a house with water in the crawl space, as it can provide the prospective buyer with a lot of bargaining power, so what can we do: I explain what to do when the crawlspace is flooded or there are simply puddles of water always standing, thus I describe how to remove quickly the water in the crawlspace and how to prevent the problem for the future. So I discuss if it is normal to have water in the crawlspace after a heavy rain, and the importance to perform a crawlspace waterproofing thereafter, normally by installing a vapor barrier.

I describe how to improve the air quality in the crawlspace and to accomplish this, I am reluctant to use lime powder in this article, where I explain the pros and cons, as I would be using lime powder only to avoid the dangers of raw sewage under the house.

We discuss the sill plate replacement cost and how to avoid the outdoor sump pump freezing because it happened to me once.

There are always new methods for repairing foundations. One of them that we investigate here is the Powerbrace foundation repair method.

Animals can be a problem when they live near the foundation: In the following articles, we describe how to remove them and how to prevent them from digging and burrowing. The articles are about animals digging holes around the foundation or when they are burrowing below concrete, below a concrete slab, or between gaps in concrete footings, for example.

In regards to basements, I describe how to solve the hydrostatic pressure in the basement, which is a lateral pressure that is the main cause for having a basement wall that is bowing, or that can be caving in or buckling. While a slight inward curve for basement wall bowing is acceptable, after that degree, you have to address the issue and face sometimes relatively high basement wall repair costs.

I provide to you some reasons why we will need a certified specialist to deal with a risky sewage backup in the basement because bacteria survive a long time in a contaminated sewage network, and also we discuss how to deal with a basement drain backing up in general and what to do when it happens only when flushing the toilet, something that is not a DYI project at all.


I explain here the process of concrete lifting or concrete raising, which can be done through mudjacking or slabjacking. We recommend the latter, which injects polyurethane foam.


There are some interesting articles here, in this Framing category. I refer to sistering floor joists, as a methodology to reinforce existing floor joists with some emphasis on sistering 2x6 floor joists or sistering with 2x8 instead, and about the building code for sistering joists, for sistering rafters, and the code for notching floor joists.

Many of these problems have a consequence: sinking or sagging floors.

Water Heaters

About water heaters, we have a complete guide about water heater types and their installation requirements, about power vent water heaters, and venting in tankless devices, and I also explain in detail the difference between a mobile home water heater and a standard water heater. I also describe in detail how to remove the heating element without an element wrench using just a socket, and how to fix leaks.

We have a few reviews when a water heater falls into our hands, such as the Titan product portfolio, Navien lineup, the Titan N-160 reviews, the most praised by our readers, and the Rinnai R94LSi.

I study several water heater capacities and tested 20-gallon water heater units and a comparison between point of use and tankless water heaters.

We open a tankless water heater to show how does it look like inside a tankless water heater, and how to protect your water heater against the effects of hard water. I also explain the pros and cons of tankless water heaters because many people consider that tankless units are better than standard heaters and it is not always the case.

After the lifecycle of the water heater is over, I reveal to you different options to proceed with its disposal.


Just because they became popular and related to current news, I study how to identify aluminum wiring and once discovered, how to proceed with its remediation or retrofit.

Pest Control

I have a featured article where I compare Orkin vs Terminix pest control services.

Photo of author

BY M. Kogan

Hello, I am Marcio. I am an architect and designer, alma mater is Mackenzie. Retired in theory, but an architect never retires completely. Along with architectural projects, I am a filmmaker and have completed some short documentaries. Filmmaking and design are my passions. In HomeQN I write about home decoration and foundations. The goal is to teach homeowners to DYI as much as possible, and when this is not possible, enable them through knowledge, to evaluate service quotations and choose the best service technicians.

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