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5 Most Common Hot Water Heater Problems And Potential Solutions

5 Most Common Hot Water Heater Problems And Potential Solutions

Hot water is one of those aspects of our lives that we take for granted—until our hot water heater has problems.

Read on to learn about common water heater problems and when they spell trouble ahead.

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Any issues with your water heater need to be solved as quickly as possible. Not doing so can lead to mold, mildew, damage to floors, and costly repairs

Before you call a plumber, make sure you do an examination of the heater and take note of anything faulty, such as: 

  1. Leaks
  2. Mold or mildew around the heater
  3. Condensation
  4. Loose pipes
  5. Loose drain valve

If you notice anything wrong with your water heater, you need to get it fixed immediately. By taking a closer look at your heater and writing down anything you observe, you can describe the problem to the plumber. 

Getting your heater fixed is crucial for your safety and your finances. The longer you let an issue go, the worse it gets.

5 Common Hot Water Heater Problems

Several things can go wrong with a water heater, but some issues are more common than others. Below are some of the most common problems plumbers encounter. 

1. Leaks

Water heater leaking from bottom for a piece on common water heater problems

Michael Vi/Shutterstock

Most of the time, a leak is not challenging to see. The tricky part is finding the source of the leak. Unless you have water spurting from a hole in the tank, chances are you have noticed water pooling on the floor underneath the heater.

That said, there are several different places a water heater can leak. Some typical spots where leaks form in water heaters are: 

  • Top of the heater – in older heaters, leakage from the pressure relief valve is a common issue. Be sure to check for the buildup of debris up there as well. 
  • Supply valve broken cold water inlet or broken hot water outlet 
  • Bottom of the tank – could be a leaking overflow pipe or drain valve.

If you notice water on your floor near your heater, put a cloth or paper towel down and check it a few times a day.

If something needs tightening, tighten the valve, and it should go away. If the water sticks around, call your plumber. The last thing you want is for your house to flood!

2. Temperature Problems

Left hand rotating a temperature knob on a water heater for a piece on water heater problems


Is your water too cold, lukewarm, or way too hot? You may be having water heater issues. If your water is too cold, it can mean that you have a: 

  • Faulty thermostat
  • Low power source
  • Broken heating element

If your water gets mildly warm but not hot enough, chances are you have too small of a water heater. This problem can only be fixed by a professional. The most dangerous temperature issue by far, though, is water being too hot.

Not only is it bad for your heater, but it can also lead to scalding, severe burns, and mineral buildup. 

The United States Department of Energy recommends having your thermostat set at 120 degrees Fahrenheit. Some heaters measure at 140 degrees, which runs up energy bills and increases the chances of future problems.

3. Water Discoloration

Dirty brown water running from a chrome faucet into a white sink


Turning on your shower and seeing water that has any color is alarming, but entirely possible if you have a broken water heater. Your water heater may be producing discolored water due to: 

  • Mineral sediment in the heater. The buildup is inevitable, so be sure to flush your heater at least once a year to prevent severe sediment buildup.
  • Rusting tank. If your cold water runs clear but your hot water is a rusty color, your water heater is reaching its final days, especially if you notice rust on the outside of the heater as well.

Mineral and sediment buildup is more dangerous than it sounds; it can cause your heater to overheat, leading it to rupture.

4. Strange Sounds and Smells

Pretty brunette woman covering her ears and looking up and to the right


Have you noticed that your water kind of smells like sulfur or rotten eggs? 

Your water heater may be to blame. Warm water that is left in the tank for too long can grow bacteria. When bacteria start to develop, they create sulfate bacteria that emit a smell reminiscent of sulfur.

To be sure your water heater is causing the smell, turn on your cold water. If there is no scent, your water heater may be faulty. 

Get this checked by a plumber immediately. If the sulfur smell is left alone, it can lead to fires and even cause your water heater to explode.

Sometimes broken water heaters make strange sounds as well. The most common complaints are a whining sound or a thumping sound. If your water heater is whining, it can mean: 

  • It needs to be flushed
  • There is too much sediment in the water

If your heater is making a low, rumbling sound, it can mean: 

  • Minerals are building up at the bottom of the tank
  • Water is trapped in the mineral buildup, causing it to boil and make a rumbling noise.

Both odd smells and sounds need an inspection to ensure your safety. 

Things to Consider

Bare chested woman covering her shoulders with her hands in an x shape and shivering after her water heater had problems


There are several things you should consider if there are issues with your water heater. Below are some suggestions on what to do and what not to do.

Find Out What Type of Water Heater You Have

There are two types of water heaters: gas and electric. Figuring out which one you have is simple. To determine which type of heater you have, you should: 

  • Remove the access panel on the side of the heater. See a blue flame? You have a gas heater.
  • Look at the top of the heater. Is there a vent? If not, your heater is electric. Electric heaters don’t have vents because they never emit exhaust. 

Clean Up Mold and Mildew

As previously mentioned, a broken water heater can destroy your floors and cause exponential damage. Check the area around the heater to ensure there is no mold forming. 

Excessive mold growth can cause: 

  • Breathing problems, especially in those with asthma 
  • Stuffy nose
  • Red, itchy eyes
  • Worsened COPD

There is concern that mold may cause memory loss, lethargy, and heart problems in infants, but these conditions cannot yet be traced back to mold toxicity. Mildew is similar to mold but tends to grow more in bathrooms and showers and has a white appearance. 

It causes similar problems like mold, too, with sinus irritation being the number one symptom. Don’t let mold continue to grow because of your water heater; it needs to be gone ASAP!

Consider Getting a Tankless Water Heater

A tankless heater could be the perfect option for you if you consistently have problems with your tank water heater.

Pros of Tankless Water Heaters

  • You’ll always have hot water
  • They aren’t as cumbersome as tank water heaters
  • Lower risk of leaks
  • Are not as dangerous as a tank heater
  • It uses less energy; your gas bill will be way lower 

Cons of Tankless Water Heaters

  • The up-front expense is generally way more than that of a tank heater
  • Tankless heaters cost up to three times more than your average residential heater
  • Water takes longer to heat up
  • Multiple water sources cannot run hot water at once
  • No access to hot water during a power outage

Investing in a tankless heater may be worth it if you have a family with young kids, though. There is no risk of explosion, and they’re less of a safety risk than traditional water heaters.

Turn Off the Power

If your heater is leaking severely, turn off your power source. If you leave your power on, it can cause fires and waste energy.

Note that the heater won’t turn off on its own. You’ll need to turn off the gas yourself. After turning off your gas line, leave your home and only return once you can no longer smell gas.

What to Do if Your Heater Has Already Caused Damage

If you get home from work one day and you notice that water is everywhere (and that the source is coming from your heater), you should, after cutting the power: 

  • Take photos of all damage to walls, furniture, floors, etc., for your insurance company
  • Move all not-damaged furniture and appliances out of the way to prevent further damage
  • Run a humidifier to prevent mold

Frequently Asked Questions

Water heater problems caused by a dirty heating element sitting next to tools


Dealing with something as challenging as a water heater is bound to stir up questions. Below are some of the most common questions people ask regarding their water heaters.

What are the signs of a water heater going bad?

Aside from the ones listed above, some other signs are reduced water flow and having a water heater that is ten years old or older.

Can a water heater explode?

Yes. Although uncommon, water heaters can explode under too much pressure or if they have severe sediment buildup or a broken anode rod.

Explosions are especially horrific if you have a gas leak in your home. The gas ignites with the water heater and causes detrimental damage.

Do water heaters give off carbon monoxide?

Carbon monoxide is only an issue with gas heaters that are not maintained. Broken vents are the most frequent cause of this problem. 

How much does it typically cost to replace a water heater?

All companies are different, but you can expect the cost to be anywhere from $1,000 to $3,000.

How long does a water heater last?

The lifespan of a water heater is about twelve years. A tankless water heater can last up to twenty years if taken care of properly.

Where should a water heater be placed in the house?

That depends on the type of heater you have. Due to regulations, Gas heaters will not be in bedrooms, bathrooms, closets, or rooms attached to those locations. 

Electric heaters, though, are safe to have in closets or other small areas.

When to Call a Pro

Smiling tech with a clipboard servicing a hot water heater that has problems

Minerva Studio/Shutterstock

When you have a broken water heater, we suggest leaving the troubleshooting to the pros. DIY’ing it can result in severe damage to yourself and your home.

In an emergency (such as water spraying everywhere), cover the leak or shut off the water main until a professional arrives. 

But as another word of caution, choosing to fix your heater yourself can lead to:

  • Severe burns
  • Carbon monoxide poisoning
  • Electrical fires
  • Gas fires
  • Flooding

Even if you consider yourself to be a handyman, the risk is just not worth it. If you think your water heater is on its last leg, call a professional.

They’ll install a new unit and give you additional options. At worst, they’ll give you a free bid.

A water heater that emits toxic materials could poison you or your loved ones. Even for a marginal issue, you should always call a professional for a second opinion. Doing so could potentially save you from property damage or worse.

Get a Quote
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We partnered with Networx to help you find local plumbers in your area. Click to below to get a FREE quote.

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We may earn a commission when you click this link, at no extra cost to you.

Notice One of These Water Heater Problems?

Honestly, water heaters are scary. They hide away in corners and garages, and ignoring them is easy until a problem arises.

To avoid flooding, toxic fumes, and even an explosion, get your water heater flushed once a year and have it replaced every ten years.

When in doubt, never hesitate to call a professional whenever you notice one of these water heater problems.

We’ve spelled out the warning signs, and it’s up to you to recognize them and take action.