Water Heater Failure – 10 Signs

Posted on by Ken Lawber

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HomeProPlumber 

This Article Discusses The Top 10 Signs That A Water Heater Is About To Fail.  

HomeProPlumber provides full service plumbing maintenance, repairs and replacements for every plumbing component in your home. We sell & install Rheem Professional Series gas & electric water heaters, and tankless water heaters.  We are near your home in Plano, Allen, Frisco, and McKinney Texas.  Homes in southern Collin and Denton Counties incur no additional travel-charges. HomeProPlumber in Plano, Texas also provides maintenance & repairs for all brands of Central A/C, Gas & Electric Furnace, and Heat Pumps.  Additionally we sell and install new HVAC Systems from American Standard (same company as Trane), Ameristar (same company as American Standard) and Coleman HVAC (same company as York HVAC).

Call us today to discuss any concerns or problems you have with your HVAC System or Plumbing.  We will arrange an appointment at your convenience and offer 24/7 Emergency Service.

How Long Can You Expect A Water Heater To Last

Click Here To See A Water Heater Diagram For Both Gas and Electric Water Heater: Water Heater Diagram

How To Determine The Age Of A Water Heater.  The first 3 digits of the serial number tell you the month and year it was made. The months are A = January and going up from there.  The next two numbers represent the year the water heater was built.

If you are researching signs that your water heater is failing, you will likely have a new one in the near future.   This seems a good time to advise how to extend the new water heater’s lifespan.  Water heaters don’t need a lot of care, and simply flushing it annually will have a notable effect on how long it lasts.  Just below, we give details about the 2 things you can do to ensure your new water heater lasts as long as possible.

How Long A Water Heater Lasts Depends On:

build up in water heater

Image Source: ShutterStock

SHOWN:  Water Heater Build-Up Resulting From Minerals In The Water

Water heaters typically last 8-12 years.  How long yours will last depends on:

  • If It’s Maintained:  Annual Flushes & Anode Rod(s) Replacement
  • How hot the water heater is set.  The hotter it’s set, the more it runs, leading to earlier failure. 
  • How “Hard” your water is (explained below)
  • How many people live in the home

The Most Important Thing That You Can Do To

Extend The Life Of Your Water Heater Is To Flush It Annually 

During heating, naturally-occurring minerals, such as calcium & magnesium, form into sediment particles that settle to the bottom of the tank (known as sediment build-up).  Depending on the source of the water, some water has higher levels of minerals. 

GAS WATER HEATERSgas water heater

Image Source: ShutterStock

Shown: Gas Water Heater

Sediment Build Up causes a GAS water heater to run longer & hotter.  This is because the sediment at the bottom of the tank must be heated before heat can reach the water.  Build up also causes “hot spots” in the bottom of the tank.  A Hot Spot is an area where there is little or no build-up present.  Because the water heater must run longer and hotter (due to build-up)  some areas of the bottom of the tank become hotter than other areas.

Metal expands when heated and contracts as it cools.  This causes stress on the metal that eventually causes the metal to crack, and the water heater starts leaking.  Once the tank is cracked, the water heater must be replaced.  The #1 reason water heaters must be replaced is because their tank cracks, or rusts through, and starts leaking.

Minimizing build-up allows a gas water heater to operate as designed to.  It heats for shorter periods of time which causes less expansion / contraction of the bottom of the tank.  The bottom also heats more evenly, minimizing hot spots that expand / contract more that other ares of the tank’s bottom.  

ELECTRIC WATER HEATERS 

electric water heater

Shown: Electric Water Heater

ELECTRIC water heaters have 2 heating elements inside the tank.  One is near the top and the other is near the bottom of the tank. As build up occurs, it often covers the lower heating element, causing it to fail.  Heating elements can be replaced, thus extending the life of the water heater.  ddepending on the age of the water heater, the cost of replacing an element may not be justified.

Because electric water heaters generate heat inside the tank (versus under the tank in gas water heaters) there is notably less expansion / contraction at the bottom of the tank.  Over time, however, the tank will crack or rust through and start leaking.   

If A Water Heater Gets Annual Flushes From When It’s New, It Will Last Longer.  

NOTE: Flushing A Older Water Heater, After Years Of Neglect, Often Causes It to Start Leaking.  

 

The 2nd Most Important Thing You Can Do To Extend The Life Of Your Water Heater Is To

Replace The Anode Rod(s) When They Wear Out.   

The Anode Rod attracts the corrosive elements in water that lead to rusting of the metal water tank.   

The two top reasons for water tank failure are stress-cracks that form from metal expanding & contracting AND rust-through of the steel water tank.  Once the water tank starts leaking, the water heater must be replaced. 

Anode Rods are typically made of magnesium, which is an easily corroded metal.  Because the anode rod is made of “softer” metal, it attracts the corrosive elements in water to it, versus them corroding the steel water tank.

Anode rods wear out long before the water heater does.  Once they are worn out (they actually disintegrate) — the corrosive elements in the water become attracted to the only other metal, the steel water tank.   Replacing worn out Anode Rods ensures that they are always present to attract corrosive properties in the water.  If anode rods are present, the steel water tank’s lifespan is maximize.

Click Here To See A New Anode Rod & A Worn Out Rod Side By Side:  New & Worn Out Anode Rod

NOTE: Replacing anode rods is not easy, as they are installed very tight.   If you are unsure of what you are doing, attempting to remove Anode Rods can damage the water heater or break the water pipes attached to it.  Unless you are incredibly handy, this is a job best left to professionals. 

 

SHOWN: Multi-Section Anode Rod. 

These are easier to install than one-piece anode rods because often there is not enough room overhead to replace a one-piece anode rod.  That would require the water heater to be disconnected, pulled out and the anode rod(s) replaced.  Then the water heater must be reinstalled.  Removing and reinstalling the water heater would cost more than the value the new anode rod presents (in the form of longer water heater lifespan).

10 Signs Of Water Heater Failure In The Near Future

You Are Starting To Run Out Of Hot Water

WITH A GAS WATER HEATER: This is typically a sign that a tremendous amount of sediment has built up at the bottom  of the water tank.  Because the burner is under the water tank, it must first heat all the sediment before it can heat the water.   During heating, a gas water heater with extensive sediment will “pop”.  We describe the noise in detail later in this article.
 

photo of electric water heater heating element Photo Source: CanStockPhoto
SHOWN: Electric Water Heater Heating Element
 
WITH AN ELECTRIC WATER HEATER:  This may mean THAT 1 OF THE 2 heating elements has failed.  It may also mean the lower element is covered with sediment (that typically burns the element out).  If an electric water heater needs a heating element, this is a replaceable part.  If an element is tested and determined to have failed, replace only the heating element if the water heater is newer.   With an older unit, the cost to replace the element may not be justified. 
 
Because the heat for the water is generated inside the tank (electric water heater) versus below the tank (gas water heater)  — the water tank is subject to less expansion and contraction in an electric water heater.   In general, this means an electric water heater’s water tank will last longer.  If a heating element has failed, you may get several more years of service by replacing the failed heating element.

Water Leaking At Its Base

You Are Increasingly Likely To See This As The Water Heater Gets Older. This typically means the water heater’s tank has either cracked or rusted through, and the water heater must be replaced.  
Click Here To See A Water Heater That Is Leaking At Its Base:  Leaking Water Heater  
 
Why A Water Heater Starts Leaking: Cracks in the tank are caused by expansion & contraction of the metal water tank during each heating cycle. While heating, the tank expands.  Once heating stops, the tank contracts.  Eventually this will cause a fracture in the metal water tank leading to leak.
 
When new, the water tank has a porcelain lining (also known as a glass liner).  Over the years the lining fails, allowing water to get to the steel water tank.  Once the glass liner fails, the steel water tank starts rusting.  Over time, the steel tank will likely rust all the way through.  You can reduce the rusting by replacing the Anode Rods as needed.

Click Below To See Inside A New Water Heater’s Tank. 

The Blue Liner Is The Porcelain On The Steel Tank.  Often referred to as the “glass liner”.

See Inside A New Water Heater’s Tank (Scroll To 3rd Row)

 

Click Blow To See Inside A Rusted Water Heater Tank:

See Inside A Rusted Water Heater Water Tank  

 

NOTE: One Exception To Water At The Bottom Of The Water Heater May Be If

The Water Is Under The Pipe Running Down The Side Of The Water Heater Toward The Floor.  

If the water is there, it may be due to the water having gotten too hot and the safety-valve opened to release pressure and / or water.  A single occasion of this is not likely a problem.  BUT if it’s happening repeatedly, the water heater is showing signs of a dangerous pattern of overheating the water.  The water heater must be inspected right away.

photo of water heaterPhoto Source: Can Stock Photo 
SHOWN: See The White pipe coming across the water heater’s top & down the side. 

Rumbling Or Popping

The noise is harmless, but excessive sediment leads to early water heater failure:

  • Eventually causes a leak–Sediment slows heat transfer to the water. This causes the water heater’s water tank to become hotter than it was designed to be.  This will damage the inner glass lining and weaken the steel water tank.  Eventually the tank begins to leak.
  • Damages the electric heating element—  If enough sediment covers the electric heating element, it will burn out.

Sediment from the water builds up on the bottom of the tank. If the water heater is not flushed annually, sediment eventually becomes hard.  When this happens, you often hear rumbling or popping sounds while the heater is heating.  Once you hear those sounds, you will typically have water heater failure within a year or two.  You can continue to safely use it until water heater failure occurs.

 Click Here To Hear The Popping Sound A Water Heater With Sediment Build-Up Makes: YouTube Popping Water Heater  

Hot Water Starts To Look Rusty

This means the water tank now has so much rust that the water coming from the water heater has rust within it.   This is a clear sign that water heater failure is near.  Water tanks are never replaced, the water heater is replaced.

Click Here To See Rusty Water Coming From Water Heater:  Rusty Water Coming From Water Heater

Hot Water Is Cloudy Or Has A Metallic Smell & Taste

The water heater’s steel water tank is corroded.  Grit & flakes from the water tank are combining with the water supply.  This requires a water heater replacement.  If the water heater has not started leaking, it will soon.  Water heater failure will occur in the near future.

 

Signs A Water Heater Needs Serviced Or Repaired

Water Leaking At The Top Of Water Heater 

Click Here To See Corroded Water Pipes At Top Of A Water Heater: Corroded Water Pipes At Top Of Water Heater

Depending On The Amount Of Corrosion:

  • It may be possible to minimize the corrosion and stop it from continuing.
  • If water is leaking where the water pipe connects to the water heater’s nipples / connectors, it’s too late.  The connectors have corroded through, and the water heater will have to be replaced.
  • If there is a plastic ring (a dielectric union) where the two pipes meet, it is there to prevent two dissimilar metals from touching (and corroding as a result).  This is a correctwater heater installation.

 

What causes the corrosion?  Two dissimilar metals are reacting with each other.  Typically a copper water line is connected to galvanized-steel water heater nipples / connectors (on the water heater) without the plastic ring (dielectric union) installed to keep the two metals from touching.

Click Here To See A Water Heater With A White Plastic Dielectric Union Installed:  Correct Water Heater Installation With Dielectric Union

NOTE: The water line may be able to be disconnected.  If it can, then as much corrosion as possible removed with with the wire-brush.  Then install the plastic (dielectric union) insert, and reattach the water pipe.  This will prevent further corrosion.  There there is nothing more you can do about existing corrosion beyond removing as much as possible).

NOTE: If there is a leak, the corrosion is rusted all the way through and there is nothing more that can be done.  The water heater must be replaced.

NOTE: Attempting to unhook the water line from the water heater can result in starting a leak.  When too much corrosion is present, forcing the water line connector with high pressure can break the corrosion loose and start a leak.  Unless you are extremely handy, this task is best left to a plumber who can determine if the corrosion is too extensive.

NOTE: A spinning wire-brush on a drill will speed this process tremendously and ensure as much corrosion is removed as possible.

The Temperature & Pressure Relief Valve Has Failed (stuck shut)

This Presents A Strong Danger Of The Water Heater EXPLODING!

All water heaters have a safety relief valve to release excess pressure and / or water if the water heater fails and continues to heat.  If this valve fails the tank can explodewith the force of a small bomb.  This often damages or destroys the home and can injure or kill occupants.

The Temperature & Pressure Relief Valve Must Be Tested Once A Year To Ensure It’s Working Properly. 

This Valve Is There Entirely For Your Safety.  If It Has Failed, It Must Be Replaced Immediately!  The T & P Valve Is A Replaceable Part.  

Click Here To See The Effects Of An Exploding Water Heater In Arizona: 

 Home Destroyed By Exploding Water Heater

To Test The Temperature & Pressure Relief Valve:

  • Put a bucket under the discharge pipe coming from the T& P Valve.  Don’t skip this step — very hot water will discharge during the test.
  • Pull the lever outward / away from the water heater for 5 seconds.  During this time hot water will discharge into the bucket if the valve is working properly

 

Burn Marks On Outside Of GAS Water Heater

Click Here To See Burn Marks On A Water Heater: Burns Marks On A GAS Water Heater

Burn marks may indicate improper venting is causing back-drafting.  This is a venting problem, and does not necessarily mean the water heater must be replaced.

Backdrafting Indicates That Carbon Monoxide Is Not Existing Your Home Properly.  

The exhaust is coming into your home’s living space (if that is where the water heater is located).   If the water heater is in the garage or attic, exhaust gases can still enter through air leaks in your home.  This condition must be repaired to ensure your safety. Problem # 2: Burn marks may indicate the flue pipes located inside the water heater are blocked or damaged.  This is also an unsafe condition which can cause improper venting of exhaust gases.  If this is the problem, a new gas water heater is needed immediately.

 

Yellow Flame At Burner Of A GAS Water Heater 

photo of gas burner with yellow flames Photo Source: Can Stock Photo

SHOWN: Yellow Flames From A Gas Burner  

When your water heater is running, there should be an even blue flame.   This is typically a correctable problem that does not require a new water heater. If The Flame Is Yellow Or Orange:

  • There is not enough air coming into the water heater’s combustion-area (where the burner is located).
  • Or, it can also mean a venting problem exists. This condition means the burner or the venting needs to be serviced to ensure your safety.  If the venting is not correct, it’s possible carbon monoxide is coming into your home.
  • Or, it could mean the burner is failing, but this is rare.

home pro plumber logo

HomeProPlumber 

HomeProPlumber provides full service plumbing maintenance, repairs and replacements for every plumbing component in your home. We sell & install Rheem Professional Series gas & electric water heaters, and tankless water heaters.  We are near your home in Plano, Allen, Frisco, and McKinney Texas.  Homes in southern Collin and Denton Counties incur no additional travel-charges. HomeProPlumber in Plano, Texas also provides maintenance & repairs for all brands of Central A/C, Gas & Electric Furnace, and Heat Pumps.  Additionally we sell and install new HVAC Systems from American Standard (same company as Trane), Ameristar (same company as American Standard) and Coleman HVAC (same company as York HVAC).

Call us today to discuss any concerns or problems you have with your HVAC System or Plumbing.  We will arrange an appointment at your convenience and offer 24/7 Emergency Service.