Informational Guide

Signs Your Water Heater Is Going Bad

The water heater is one of the most important appliances in a home. Our guide will help you learn the different signs your water heater is going bad.

by Ian Haynes

The heater is one of the most important appliances that you have in your home. You’ll want to make sure that you can recognize the signs that it’s about to go bad and to know when to replace one before it fails.

That way, you can make the repairs or replacements beforehandThis guide will help you by teaching you all of the signs water heater is going bad. 

1. Not Enough Water

First of all, you feel like there’s never enough hot water for more than one person to shower per day. You may want to get a new unit. This means your water heater isn’t producing enough hot water during the day or is running very slowly.  

You can try changing the temperature dial on the unit to a higher one. Wait for an hour, then try to shower. If you still get cold water, something is wrong. Over time, the minerals in your water create a layer of sediment at the bottom of the tank. The more this builds up, the less room there is for hot water storage.  

2. Varying Water Temperature Issues  

Maybe the water switches between being too hot and too cold? You’ll want to check that out too. Fluctuations can be a sign that your water heater is getting ready to fail on you. You’ll want to do some minor investigating before buying a new one. 

Start by checking the thermostat on the unit. Mark where it is or take a picture, then take a shower. If the thermostat isn’t in the same place when you’re done, it’s failing. 

3. Water Heater Leaks

It goes without saying that leaks are bad. You should never see water around the tank! It is a sign that a failure is coming to the appliance. Make sure that you shut down the power sources (electricity and gas) before inspecting the unit.  

If you can’t make the repairs on your own, be sure to reach out to a licensed plumber for assistance. They can find what screws are loose or other problems. Sometimes, the fix is as easy as having the drain valve replaced, as they become weak with age. However, a leak may also signify a replacement is needed. 

4. Reduced Water Flow  

Drastic changes in water pressure are likely a sign of build-up in the water system. You'll want to take care of it now, so it doesn't become a more expensive fix in the future.

You can always drain the tank and clean out any debris that you find inside after safely shutting down everything. You can also have a pro come out and descale your system for you. 

5. Noisy Water Heater

If you're hearing a lot of weird pops and bangs, then the water heater is probably not running efficiently. There are many sounds that can indicate problems, so it's best to make an appointment with a licensed plumber.  

The sounds could be coming from a broken heating element or sediment burning off in the machine. Plus, boiling and overheating can be serious issues. Shut down everything and drain the water. Next, you'll need to take a look inside. If you can't find any build-up to remove, it's best to call a pro. 

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6. Smelly And Discolored Water  

Bad water is an indication that something isn’t right with your water. However, it could be with the source of your water, too, not just the heater. You'll want to run a hot tap, then a cold one into a clear glass. From there, you can inspect the water. 

If there are issues with both temperatures, then the water is spoiled from the source. On the other hand, if it's just the hot water that is discolored, then you have a hot water issue on your hands. 

7. Water Heater Is Old/Aging   

Finally, age is a common sign that something could go wrong with your hot water system at any time. Older machines can run into several problems when they're nearing their natural end of life.

You'll probably want to replace it before you start running into all of the above issues at one time. As a general rule, think about replacing your water heater when it’s older than 10 years. 

Check out our best water heater reviews here

Water Heater Going Bad

Symptoms Of A Bad Water Heater (Main Components)  

  • Bad Thermocouple 
    There are several signs that your thermocouple is about to fail. You’ll notice contamination on the tubes, worn-out wirings, or faulty connectors. When this part breaks, you won't have a reliable source of hot water anymore. It's best to deal with it immediately.  
  • Bad Water Heater Dip Tube
    When the dip tube breaks, cold water mixes with the water that’s already been heated- giving you lukewarm or cool water when you use the hot taps at home. The dip tube can go bad as time passes, making it essential that you change it out when you notice this issue. 
  • Bad Water Heater Element 
    If the heater element is starting to go, you’ll notice lukewarm water more often than not. You’ll also only get a burst of hot water at the start of your shower. Then, only cool water. It will feel like the hot water runs out really quickly. The water heater’s circuit breaker may even start tripping- it’s best to have a pro come and look at it! 

Signs That A Water Heater Is Going To Explode  

  • Leaking Pressure Valve  
    A leaking pressure valve is very dangerous. It ensures that the tank doesn't build up too much pressure- leading to an explosion. A lousy valve will surely lead to a disaster. 
  • Rotten Egg Smell  
    This smell is linked with sulfur- which means there’s a gas leak! You need to call a professional immediately. Don’t try to mess with this one alone. 
  • Popping Noises  
    This may mean that there’s a ton of build-up at the bottom of your heater. You'll need to drain it and clean it out. 
  • Brown Water 
    When you notice gross, brown water, you need to reach out to the pros immediately. This means that sediment or rust is contaminating your water- which is very bad for your health. It could also lead to an explosion if not taken care of. 
  • Bad Installation
    A bad installation can cause all sorts of problems, which can lead to explosions. If you have any problems at all with a new heater, you'll need to have another team of experts come out and look at it. 

When To Repair Or Replace Your Water Heater?  

When trying to determine whether it’s best to repair or replace the unit, you want to think of its age first. If the unit is less than 10, you can repair the broken parts. If it’s above 10, you’ll want to replace the machine instead. After 10 years of consistent use, old machines start to develop many more problems. 

That means it's more worth your time to make the replacement- you'd end up dealing with several issues that could lead to a lot of damage. Still, it's best that you look into the parts that are broken. Some are very cheap anyway. 

Man Replacing Water Heater

The Importance Of Water Heater Maintenance (Tips To Extend Life)   

It’s essential that you take the time to maintain your water heater. You can do this by performing a hot water maintenance flush every single year. Most people never do this, causing several issues to arise in their unit. This method flushes the sediment and debris out of the unit, allowing you to get more use from it. 

First, always shut off the gas and electricity. It’s important to keep yourself safe. Then connect a hose to the drain valve at the bottom of the hot water heater. You’ll want to direct it to a place where you can dispose of the dirty water, without touching it- the water that comes out will be burning hot! 

Turn off the cold water and run a hot water faucet somewhere else in the home. The water that runs out of the hose will look gross, so you should run it until it's completely clear again. 

People Also Ask (FAQs)

How long does a water heater last? 

Today, most hot water heaters last about 10 years. After that point, you need to start watching it for signs of damage. You may want to consider a replacement the closer it gets to 15 or 20. 

Which has the longer lifespan: Electric or Gas water heaters?  

Electrical heaters last longer- they can get up to 12 years of age. Gas ones only last about 10 years on average. 

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

The amount of life you get out of a leaking heater depends on what you do next. If you let it continue leaking, it could only have weeks or months. You’ll need to make repairs to get it to last years. 


Those were all the signs that it’s time to replace your water heater! Make sure you know and can recognize them, in case they start happening at home. 

Ian Haynes is an expert writer who has successfully deployed over 500 plumbing pages and other related content. He has an excellent understanding of home plumbing issues and translates his experiences via Plumbing Lab so readers can have a better understanding of common household problems. Outside of his work, Ian likes exploring Brooklyn with his Labrador.