Hot Water Heater Leaking from Top, Bottom or from its Tank – Full Guide



Can you imagine living in a house without hot water? Not a nice feeling, right?

Water is naturally cold, but depending on the season, it can become a bit warmer. We all know what happens to water during the winter, so you definitely need a water heater to have a continuous supply of hot water.

A hot water heater is a cylindrical device that works together with the pipe system in your house to heat and deliver water at a desired temperature. It is attached to either point-of-use systems or centralized usage.

As you use your water heater over and over again, there may come a time when you notice a pool of water underneath your heater’s tank. This means that the device is leaking and it should be fixed immediately to avoid further problems.


How much new water heater installation costs?
Water Heater Repair
$150 - $300
New Water Heater
New Gas Water Heater Cost:$800 - $1100
Tankless Water Heater
$1500 - $2500+

See costs in your area Start Here - Enter Your Zip Code


How Much Water Heaters Cost to Replace / Install?

We have a detailed guide on hot water heater replacement costs, but here is a quick overview: If you feel that your unit is beyond repair, replacing is the only way out. However, new water heaters are not that expensive, so let’s take a look.

You can have a basic 45-gallon tank gas or electric heater installed for $750-1000, including labor and materials!

A larger tank, better efficiency unit, can cost from $1200-2500.

A tankless water heater can run between $1500-3000, although I’m NOT convinced tankless is better. This decision you should make on your own. Do you want to put more money upfront, and save on operating costs, or you prefer to pay less in the beginning, and pay slightly more as you go.

All these questions and more, we answered in our water heater costs guide.


How much new water heater installation costs?
Water Heater Repair
$150 - $300
New Water Heater
New Gas Water Heater Cost:$800 - $1100
Tankless Water Heater
$1500 - $2500+

See costs in your area Start Here - Enter Your Zip Code


Common Causes of Water Heater Leaks

There are a number of reasons why your hot water heater may start to leak. Here are the most common ones to look out for:

  1. Water Heater Age – any water heater will eventually come to the end of its useful life and start rust and corrode. This process leads to leaks. Typically, tank-style heaters last 8-12 years, while tankless devices can last a little over 20 years.
  2. Poor Installation/Plumbing – to ensure that your device lasts and works without problems, it should be correctly installed. Many water heaters start to leak prematurely due to a poor plumbing job done during the the installation. While its possible for an experienced DIYer, familiar with plumbing and electric to install a tank-style device, tankless heaters should only be installed by a pro, because there is a lot of complex plumbing work involved. Its better to pay more for professional installation, than suffer from leaks and other problems, which will still force you to spend money on repairs.
  3. Tank or Pipe Holes – Well, there could be some tank or pipe holes that cause the leaks. It won’t hurt to have everything checked before and after installation, right?
  4. Lack of Maintenance – like most devices, a water heater should be maintained and checked once in a while. This will ensure its efficacy, save money and prevent accidents.
  5. Loose Drain Valve: this issue is a frequent cause of leaks. When the valve gets too loose, it will slowly start to leak water.
  6. Excess Pressure Inside the Tank: if too much pressure builds up inside the tank, it forces the water to leak out, to release the pressure. This often happens when the temperature on the heater is set too high. Other possible causes of high pressure are: 1. overly high pressure of the exterior water supply coming into the house. 2. defective temperature pressure relief valve.

How much new water heater installation costs?
Water Heater Repair
$150 - $300
New Water Heater
New Gas Water Heater Cost:$800 - $1100
Tankless Water Heater
$1500 - $2500+

See costs in your area Start Here - Enter Your Zip Code


How To Check For a Leak In Your Hot Water Heater

Before you spend money and call in a plumber, you can preform a basic check to locate the source of the leak in your hot water heater. If you don’t have experience dealing with gas or electric appliances, its better to be on the safe side and call a pro.

  1.  Inspect every part of the water heater: carefully check check every part of the device: the tank, valves, pipes, etc, to locate the source of the leak. Make sure that all parts are well-fitted to its connecting parts, as this can also be a source of the leak. If you find any wet parts, be sure to dry them thoroughly. Check back in a few hours to see if the area is wet again. If yes, then you have found a water leak! If not, then you’re lucky, and is wet due to normal condensation.
  2. Turn off the power source: if you find out that there is a leak, be sure to turn off the power source. Never forget to do this to avoid accidents.
  3. Switch off the water source: usually this part is at the shut off valve of the cold water. If the leak is not located yet, just leave it open for a while, as it could help find the source of the leakage.
  4. Check the cold and hot water pipe connectors and inlets
  5. Check the pressure valve and temperature controller
  6. Check the drain valve: make sure that its closed fully and not even a water drop can pass through it.
  7. Check underneath the hot water container: this is a common area where leaks are discovered.


5 Easy Steps to Fix Hot Water Heater Leaks

Here is a brief summary of the steps you can take to try fixing the leak by yourself. If you find that it didn’t work, call a professional plumber.

  1. If the leak’s source is cold and hot water pipe connectors and inlets, it is usually due to loose connections. The easy fix is to tighten the connection.
  2. If the leak’s source is the pressure valve and temperature controller, this could be due to overheating or high pressure inside the container or tank. The easy fix is to set the thermostat to a lower number. Check everything after turning on the power and the water source. If the problem is still the same, turn everything back off.
  3. If the leak’s source is a poorly installed or bad pressure valve, you will need to replace it. This is a more complex job to tackle on your own. Here is what you need to do:
    1. Put a pale or anything that can hold water under the discharge pipe.
    2. Take out any foreign or faulty small parts after the valve is flushed out.
    3. Drain out the hot water. Make sure it is below the valve level. Water will not be coming out if it is in that part already. The hot water faucet in the sink should be opened to let air come freely inside the container or tank.
    4. Close the valve going to the left until it comes off.
    5. Put the new one tightly taping it into the grooves. Use the channel locks and turn it until it is fully tight and secured. 
    6. The hot water container should be refilled after the old valve was replaced with the new one. 7. Inspect the faucet in the sink you opened earlier and if the water is flowing strong, turn the water heater power on.
  4. If the leak source is the drain valve, the easy fix is to place a water container below the valve and turn it to the left, to let out debris. You will need to replace the valve, if it is still leaking after the flush. Use the steps outlined above.
  5.  If you discover that the heater is leaking from below the tank, it may be that you need to completely replace it. In this case, don’t try to dismantle the water heater and do repairs by yourself, as it could be dangerous. Call for professional help.

How much new water heater installation costs?
Water Heater Repair
$150 - $300
New Water Heater
New Gas Water Heater Cost:$800 - $1100
Tankless Water Heater
$1500 - $2500+

See costs in your area Start Here - Enter Your Zip Code


If you find that the water heater is still leaking after the repairs you have attempted, turn off all the water sources, and get a licensed plumber. Tell him everything you did from the start – what you noticed, when the leaking first started, what fixes you tried, etc. Never leave out a single detail as it could be a clue to finding the problem.

What If Your Hot Water Heater is Leaking From the Top?

Having a leak from the top of a water heater is not as critical as having one from the bottom. But, if it does happen, there are just two main causes:

  1. Loose pipe fitting:. If you find a leak at the top of the device, it indicated a problem in either your inlet or outlet. The inlet is where cold or unprocessed water enters the vessel. Check if the tubing is loos or torn. If the tubes are loose, you can use a pipe wrench to tighten it. If the tubes are torn due to old age or as a result of external factors such as rodents, then its best to call a plumber to remove and replace the tubing.
  2. Pressure valve is not watertight: It is located at the top of your machine. Sometimes it causes water to leak from the top to sides. Inspect the valve for any defect. Drain the tank until the water level is below the valve, then open the hot water tap to let the air come inside. Next, unscrew the valve using a pair of channel locks. Take a closer look at the valve and look for any rust and corrosion. If there is none, then you can just seal the valve before returning it to the tank.

What if Your Hot Water Heater Leaks at the Bottom?

A leak from the bottom of the tank looks like a pool of water, and can be an indicator of a serious problem with the device. There are three reasons why this thing happens:

  1. The temperature and pressure valve relief is leaking: this valve is designed to release water if there is too much pressure inside the tank or the water is too hot. It’s supposed to be an automatic regulator to avoid hazardous explosions, but at times it can actually cause leaks. The valve is equipped with a discharge tube that runs from the valve to the floor. The tube makes the water that leaks go directly towards the floor rather than outwards, where it can be more damaging. If you find that pressure is not the problem, and the valve itself is faulty, you should replace it.
  2. The drain valve is leaking: Every water heating device has a drain valve that is located at the bottom of the tank, where it is used in draining the tank and in removing the sediments. If the valve is faulty, it can actually create a pool of water at the bottom of your tank. In this case it should be replaced. Another reason for leaks can be that the valve is not tight enough, causing the water to seep at the edges. In this situation, you can simply tighten it.
  3. The water may leak from the tank itself:. this can be caused by a built-up of sediments over the course of years of usage. Sediments that have been collecting inside for a long time can start to cause cracks and rust inside the tanks, eventually leading to leaks. Usually, this situation indicates that its time to replace your tank with a new one.

How much new water heater installation costs?
Water Heater Repair
$150 - $300
New Water Heater
New Gas Water Heater Cost:$800 - $1100
Tankless Water Heater
$1500 - $2500+

See costs in your area Start Here - Enter Your Zip Code


Preventing Water Heater Leaks

The secret to having a long lasting water heater is to perform REGULAR maintenance. Similar to maintaining your car, this will extend the life of your heater and its parts. Here is what you should do:

1. Check the anode rod annually, and replace it if need be.

2. Flush your hot water heater at least once a year to prevent sediment build up, leaks and other problems in the future.

3. Test the Temperature Pressure Release (TPR) Valve a few times a year. To do this, first turn off the power and the water supply valves. Then, place a bucket connected to the pipe of the TPR valve. Next, lift the valve’s tab to let some water out, and let go. If you see that the water continues to leak out, partially drain the tank, and replace the valve with a new one.

4. Insulate the water pipes with self-sticking foam insulation (you can get it in any big box home improvement store). This procedure will help prevent condensation in the summers.

5. Insulate the heater using a blanket made from R-4.5 foil-covered bubble wrap. Be sure to make cut outs around TPR valve, piping, and temperature control. You should NEVER cover the top of an oil or gas heater.


How much new water heater installation costs?
Water Heater Repair
$150 - $300
New Water Heater
New Gas Water Heater Cost:$800 - $1100
Tankless Water Heater
$1500 - $2500+

See costs in your area Start Here - Enter Your Zip Code


The Best Temperature Setting for Your Water Heater

Maintaining the right temperature can also significantly prolong the life and efficiency of your hot water heater. It’s a capital N-O to set your device at a very high temperature. It can lead to leaks and other problems, depending on the type of device you have.

Here are some guidelines to setting your the temperature:

The recommend setting it 120 degrees Fahrenheit or 49 degree Celsius, as safety measure to prevent scalding from tap water. For children or elderly individuals, who may be more sensitive, the setting may need to be adjusted to 110 degrees Fahrenheit.

You should turn off the water heater off completely, or turn the thermostat down to its lowest setting if you go away from your house for three days or longer.

Finally, you should know that for every 10 degrees you lower the temperature, you can save up to 5 percent in energy costs.

Damages and Accidents Caused by Hot Water Heaters

It is important to follow proper safety procedures to avoid any damages and accidents that can be caused by inappropriate water heater use.

Scalding and burns: if the temperature on your water heater is set to high, you can burn seriously burn your skin when washing your hands or taking a shower. Heat can cause burning or scalding in as little as 5 seconds. To avoid this type of injury, your water heater should have a tempered valve. It acts as a regulator that mixes cold and hot water. In the absence of a tempering valve, you can just lower the heater’s set point temperature.

Sanitation: bowls, basins, tanks and other containers that have stagnant water can become major breading places for microbes and bacteria. Legionella may develop in tanks with water, which is not hot enough. This is a negative strain of bacteria that can even survive in warm water. If taken orally or inhaled, this bacteria can infect the alveolar macrophages, developing into Legionnaire’s disease. Luckily, Legionella can be controlled by raising the temperature of the tank even at least once a day. However, tank temperature above 60 degrees Celsius can produce lime scale deposits, which could later harbor bacteria.

Explosion hazard: any hot water tank is potentially dangerous, because anything that contains heat may explode. That’s why temperature and pressure valves are created to regulate the internal homeostasis of the tank. It is located in the upper portion of the device to dump water in case the temperature or the pressure gets too high, thereby preventing an explosion. Another important safety measure against an explosion is to properly install your heater in the right place inside your home, following all plumbing codes and procedures.


How much new water heater installation costs?
Water Heater Repair
$150 - $300
New Water Heater
New Gas Water Heater Cost:$800 - $1100
Tankless Water Heater
$1500 - $2500+

See costs in your area Start Here - Enter Your Zip Code


16 thoughts on “Hot Water Heater Leaking from Top, Bottom or from its Tank – Full Guide

  1. Latoya

    I would like to know what other problems can this cause by your hot water heater tank leaking and not repaired? I’m asking theses questions because I am renting a house and my landlord is cheap and doesn’t want to buy a new one. Now can this run my water bill up?

    Reply
  2. Latoya

    hello, my water heater tank is leaking from the release valve. Now can this part be replaced or do I have to get a whole new tank. Now my tank is old it was made in 1994 but the only leak I have is in the release valve where you release the water at. Another question I have is. Does this run your bill up by leaking?

    Reply
    1. levab Post author

      Hi Vickie,

      You pretty much cannot patch a leaking hater heater. Success rate is too low, and even if you succeed, it will be very short time until it leaks again.

      With that said – obviously success chance is much higher, if leaks is somewhere at the top, vs bottom…. but that is also very unlikely.

      Sorry for bad news. Good luck.

      Leo

      Reply
  3. Aruna B Upadhyaya

    I am getting boiling hot water even in the basin tap which has no mixing tap when the hot water tap is on in the mixing for bath .What could be the reason? Solution please!

    Reply
  4. Peggy Patterson

    my tank seems to have a leak at the top rim of the tank…. not at any valves… not all the way around just on one side.

    Reply
    1. levab Post author

      Hi Peggy

      Sorry to say this, but if tank itself is leaking – there isn’t much you can do – it rusted too much, and even if you fix the hole, it will leak again. This is one of those cases when you need to have it replaced.

      I just had my tank replaces, because it rusted through on the bottom… it was a small drip, so I glad I caught it in time, before it became a flood.

      Depending on where you live and the tank type / size you get, you are in for $750-1000+ …

      Good luck

      Reply
  5. Leaky

    Can a small electric tank leak (rust) be patched with a liquid cement or other product for a week or less, while waiting for a plumber to switch out my new tank? A product that will not catch fire after tank gets hot. My tank appears to be leaking just below the element. I have some Black Jack all weather roof cement that is waterproof, but warns that it is combustible. I don’t know if it will catch fire after it is dry or if the tank even gets hot enough to start a fire and don’t want to take a risk, but if I can seal the leak for a few days that would be helpful. Meanwhile, breaker is turned off, but I have to turn tank lines on to take a shower. Not talking about a hot shower. The shower will not even run, unless valves from tank are turned on, but when they are on, it leaks.
    Cold showers in the summer are not a problem. I’m trying to save money, instead of the price for an emergency repair.

    Reply
    1. levab Post author

      @Leaky

      I don’t believe the tank gets hot enough to start a fire, because you always have water in tank, and it never goes even to boiling point. Roofs get hotter than water in the tank, or just about the same.

      That said – if leak is in proximity of the heating element – it is a risk.

      And last – roof cement WILL NOT work – it’s not made to be applied to wet surface.

      If you used Water Stop (Water Cut-off) roofing sealant, it would stop water, but it’s so gooey and soft, that water in the tank will just break the seal.

      I believe that plumbing stores sell patching material that may hold the leak for 1 week. Give them a call.

      Reply
  6. Rob

    Can I shut off main cold water inlet to tank and run just cold water throughout the house until I fix the problem

    Reply
    1. levab Post author

      Rob, yes, sure you can do that. But if you shut off cold water in, you need to make sure you put tank on pilot (or shut off power if its electric), so you don’t overheat the water inside the tank.

      You don’t mention what the problem with your tank is.

      Leo

      Reply
  7. Derek Mcdoogle

    Recently my family and I just moved into a new home and there is no hot water in the house. You mentioned that typically tank-style heaters last 8-12 years, while tankless devices can last a little over 20 years. I wonder if that is the reason why it stopped working. Which type of heater do most plumbers prefer?

    Reply
  8. Andre Beluchi

    The advice that mentioned about letting the professional handle the installation of a water heater sounds like a good idea to share. It’s an advice that I would share with my sister who’s been thinking about doing a new water heater installation at her house. Mainly because of my fear that she might mess something up with the installation.

    Reply
  9. Server

    Most leaks come from the hot water tank itself. If the tank is leaking, there is an internal problem, and likely one of the components has sprung a leak, causing water to slowly leak out and pool at the bottom of the tank.

    Reply
  10. lellylel

    Hi there,

    I found this very interesting,
    I have a couple of Q’s
    am I able to post pics of my boiler, to establish if there is a way to access inside to see if I can repair a leak.

    thanks

    lellylel

    Reply

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