Water Heater Leaking From The Top? (We Have A Fix)

Water Heater Leaking From The Top

Water heaters leak; it’s a fact of life. While it can be extremely frustrating, it might not be that bad. When your water heater leaks, the best thing you can hope for is that the leak is coming from the top: That is the best-case scenario. As long as it is caught in good time, a leak that originates from the heater’s top can almost always be repaired.

If there is water in the bottom of your dishwasher, it is most likely due to your garbage disposal, a dirty filter or drain basket, a clogged drain hose, or a closed off air gap. Begin by running the garbage disposal on for 15 seconds. If the problem persists, trying cleaning your filter basket.

While the issues can be many, it’s more likely to be one of these three. The good news? It’s easy to fix.

This article will go over what might be causing your water heater to leak from the top. Also, we walk you through the diagnosis phase and explain the costs for each type of repair. We put all the information in one place for you so that you don’t have to search; We did the searching for you.

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Locating The Origin Of Your Leak

The first thing you need to do is locate the origin of the leak. Before working on your water heater, we strongly advise that you switch the power off for safety reasons. You don’t need to run the risk of electrocuting yourself.

If you have a gas water heater, switch off the gas supply by turning the thermostat control to the OFF setting. However, if your water heater is electric, switch off the power supply by turning the circuit breaker on your electrical panel to the OFF position.

Instructions To Find The Leak

  1. Find the cold water inlet. Once you are satisfied that the power supply is closed off, find the cold water inlet. This is the pipe that allows the water to fill the tank in order to be heated. Leave the valve in the ON position so that it will be easier to identify the source of the leak.
  2. Dry the top of the water heater. Using paper towels or rags, dry the top of the water heater in the area where the cold water inlet pipe enters the tank.
  3. Inspect all the lines and rubber seals. Use a paper towel to see if you can identify precisely where the water is leaking out from. Place the paper towel on all the lines and rubber seals. If the paper towel ends up wet, you have found your leak.
  4. Shut off the cold water inlet valve. Once you’ve found the likely source of the leak, shut off the cold water inlet valve by turning it to the OFF position. (This is the valve positioned on the pipe which supplies cold water to the inlet on the water heater).
  5. Mop up the area to check that it remains dry. At this point, the leak should stop, and once you’ve mopped up any water, the site should stay dry. Taking this action will prevent any more damage from water pouring down the outside of your appliance.

Common Causes Of A Leaking Water Heater

A leak from the top of your water heater will most likely be due to one of three typical causes:

When you discover water pooling on top of the water heater, it’s generally a sign that the leak originates from either the water inlet pipe or the water outlet pipe.

Cold Water Inlet Valve

The first step you should take is to inspect the cold water inlet pipe. Look for either a ball valve or a gate valve that enables you to turn off the supply of water. A ball valve will have a lever to switch the flow on or off. If the lever is parallel with the pipe, it means that the valve is in the open position, so cold water can flow into the tank.

  1. Inspect the valve for signs of leakage. If you realize that drops of water are coming out, the answer may be as simple as a nut that turns the handle has become loose.
  2. Tighten the nut. If the nut is the issue, merely tightening it should solve the problem.
  3. Replace the valve. If tightening the nut doesn’t resolve the issue, and the leak recurs even when the nut is tightened correctly, the cause is more likely to be a faulty valve. You will need to remove the valve and replace it with a new one.

Loose/Corroded Pipe Fittings

Note: It’s important to note that certain water heaters may have been installed using copper tubing rather than threaded pipe. Working with copper is a whole different ball game.

If you’re not experienced in the work type, we recommend that you consult a qualified plumber who will advise and carry out the repairs needed.

  1. Inspect the water inlet and outlet fittings. These are also known as dielectric nipples. Look for any evidence of dripping water. Take special care to check the pipe’s connection point, the dielectric nipples, and any other junction points.
  2. Tighten the pipe using a wrench. Should you realize that the leak is due to an issue with one of these connection points, it is easy to solve the problem by merely tightening the pipe using a wrench.
  3. Replace the entire fitting. It is not uncommon for the nipples to corrode over time. Should this have happened, the whole fitting will have to be replaced. A much more severe problem is if the rust has spread to the tank itself. If that, too, has begun to rust, the only solution is to purchase a new water heater and replace it.

Temperature & Pressure Relief Valve

A temperature and pressure relief valve (also known as the T&P valve) will be situated either on the top of the tank or on one side.

  1. Inspect the area around the valve carefully. When you observe water leaking out from the threads of the valve, it will have to be removed so that you can decide whether this is the source of the issue.
  2. Replace the Valves. In general, it tends to be better to substitute a faulty T&P valve with a replacement as it can’t be fixed easily. T&P valves are installed for safety reasons, so it is in your interest to ensure that it is a good state of repair.

The Cost Of Replacements

Replacement Costs
Part Low Typical Range Average High
Inlet Valve $13 $17 – $35 $33 $70
Fittings $14 $39 – $57 $45 $125.00
Pressure Relief Valve $12 $17 – $25 $22 $40
Water Heater $400 $650 – $1,611 $933 $5,000

Inlet Valve

Most often, homeowners discover that the inlet valve is usually the primary source of their leak. Since this is cheap to replace, it might be better to replace it rather than fully fix it. Unless, of course, the nut needs to be tightened.

The average cost of an inlet valve for your water heater is about $33. However, this price can range as low as $13 to as high as $70. The cost factors depend on the type of water heater you have. Inlet valves that are uncommon tend to be a bit pricier.


Upon finding that your fittings are rusted or corroded, you will need to replace them. There is no fixing damage caused by rust. However, from now on, perhaps it would be better to check every few months for water leakage. That way, you can keep your fittings free from corrosion.

To replace the pipe fittings on your water heater, it will cost around $45 on average. Now, this price can go up to $125, but that is for the top of the line equipment, which may not be necessary in your case. However, the lowest that you can expect to pay is around $14.

Pressure Relief Valve

The pressure relief valve can’t be fixed unless, again, the connections aren’t tight enough. In the event that your pressure relief valve is the issue, you will need to purchase and install a new one. This is because usually, the threads are the culprit.

Most people pay between $17 to $25 for a pressure relief valve for the water heater. The average price stands around $22. This does not include the cost of a professional. However, this fix is quickly done as a DIY project.

Water Heater

Sometimes you will find that you need to replace your water heater. This is the absolute worst-case scenario, but the bright side is that you’ll so have a fully functional, problem-free water heater for your home! If you need to replace your water heater, the price varies greatly depending on the kind.

In general, you can expect to pay around $650 to $1,611 for a brand new water heater. Now, if you’re a single person living in a small place, you could get away with paying $400. However, if your house is much larger, you might find yourself paying an upwards of $5,000.

When To Hire A Professional

Depending on the state you live in, you might need to hire a professional to install a water heater. This is to ensure everything is up to the plumbing code. If you do this yourself, you might be required to have a professional check your work. If it’s a simple fix, don’t waste your money on the labor you can do yourself.

One thing is for sure, though, you will most likely need a permit. To obtain one, contact your local building authority and talk to someone about the steps you need to take. However, most individuals prefer to hire someone because they don’t like dealing with permits. The professional will take care of all of that, and the price is usually included in the quote.

Cost To Hire A Professional

Professionals can be costly. However, they have the expertise to get the job done correctly. When you ask a professional for a quote, this price usually includes the following:

  • Any permit fees
  • Cost of equipment
  • Removal of the old tank
  • Price of labor
  • Installation
  • Clean up
  • Disposal (Although this might come at an extra cost)

The installation cost alone will be anywhere from $220 to $650, depending on the tank’s size. This doesn’t include the per-hour labor cost. The labor fees range from $65 per hour to over $200 per hour. Although, you will find some plumbers will charge a flat fee. Make sure to get at least three price quotes before you choose.

Related Questions

Is a leaking water heater an emergency?

A leaking water heater could be a sign that something more serious is wrong. However, it’s not an emergency unless your water heater is gushing water. Clean the leak up, and follow the information above to determine where the leak is originating from.

How long will a water heater last after it starts leaking?

If the water heater itself is what’s leaking, then that’s a sign that it’s old. However, with continued proper care and small fixes for the leak, it can last about 10 to 15 more years maximum. Typically, you will need to replace it in 5 to 7 years.

Is it dangerous to have a leaking water heater?

The water heater leaking isn’t a danger within itself. However, the potential for mold to spore and seep into the foundation of your home is what will be the biggest issue. Foundation repairs can be very costly, so it’s better to take care of a leak sooner rather than later.

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Our Takeaway

A leaky water heater isn’t usually a cause for immediate concern. However, due to the risks it poses to your foundation, you need to take care of this issue as soon as you can. Find the origin of the leak so that you know whether or not it can be repaired. Replacing a water heater is expensive, but it needs to be done as soon as possible if the water itself is the issue.

Heather Robbins

Heather is a passionate writer who loves anything DIY. Growing up, she learned everything from home repairs to design, and wants to share her tips with you. When she's not writing, she's usually hiking or searching for her next DIY project.

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