10 Signs Of Upcoming Water Heater Failure Or A Repair Is Needed

We Compiled The List Of Top Signs Of Upcoming Water Heater Failure.   Some problems can be repaired, others require water heater replacement.  We have detailed what must be done to correct each problem below.

How Long Will Your Water Heater 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.

Water heaters typically last 8-12 years.  All water heaters eventually wear out.


How Long A Water Heater Lasts Depends On:

How many people live in the house (more people = more hot water usage)

How hard the water is.  “Hard” water typically refers to how much lime is in the water.  Lime builds up on every plumbing component.  Over time, the component can no longer perform as designed and that leads to water heater failure.

photo of lime build up on a faucet

Photo Source: Can Stock Photo

SHOWN: Lime Build Up On A Bath Faucet

Sediment buildup: When water is heated, minerals in the water separate and settle to the bottom of a water heater’s tank. Over time, this buildup reduces the water heater’s ability to perform and often leads to water heater failure.  This is especially an issue if you have hard water.

Maintenance-1: If a water heater is flushed annually from when it’s new it will last longer.  This is even more so for gas water heaters, as the gas burner is below the tank.  In electric water heaters, the heating elements are inside the tank.  Flushing the water heater removes a lot of the sediment build-up at the bottom of the tank.

Maintenance-2:  Replacing Anode Rod.  This rod attracts the corrosive elements in water that lead to rusting of the metal water tank.

NOTE: Replacing these rods is not easy, as they are installed very tight.  If you are not sure 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 for water heater service people.

 Click On The Photo To: View Product, See Details, or Buy From Amazon.com  NOTE: A specific anode rod is required for each water

Signs Of Upcoming Water Heater Failure

1. You Are Starting To Run Out Of Hot Water


This is typically a sign that a tremendous amount of sediment has built up at the base 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.

Click Here To See Sediment Build-Up In An Older Water Heater: Sediment Build Up Inside A Water Heater

NOTE:  This is not the time to start flushing your older water heater, or for the first time in years.  Flushing an older water heater, after years of neglect, often causes it to start leaking.  In many cases, the sediment is plugging holes in the bottom of the water tank.  You can flush it, but do so with the expectation it may start leaking.

NOTE: If you flush it, and it doesn’t start leaking (and you now have plenty of hot water) you can extend the water heater’s life a few more years.

NOTE: If the water heater is located where it can cause damaged to the house, especially in an attic where hot water could come through the ceiling, it may be best to replace it and do annual flushes on the new one going forward.


photo of electric water heater heating element

Photo Source: CanStockPhoto

SHOWN: Electric Water Heater Heating Element

This may mean one of the two 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.

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.

2. 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.  You have experiened water heater failure and it 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.  These expansions & contractions occur during each of thousands of heating cycles.  Eventually this will cause a fracture in the metal water tank leading to leak.

When new, the water tank has a porcelain lining.  Over the years the “glass” 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.


Click Below To See Inside A New Water Heater’s Tank.  The Blue Liner Is Porcelain On The Steel Tank.  Often It is referred to as the “glass liner”:

See Inside A New Water Heater’s Tank

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

See Inside A Rusted Water Heater Water Tank


NOTE: One exception may be if water is located near the pipe that channels water 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 has developed a dangerous pattern of overheating the water.  The water heater must be inspected right away.

photo of water heaterPhoto Source: Can Stock Photo

SHOWN: White pipe coming across the water heater’s top & down the side is there to safely allow hot water to escape from the tank because it got too hot.

3. Rumbling Or Popping

The noise is harmless, but excessive sediment leads to earlier 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 See Sediment Build-Up Inside A Water Heater: Sediment Build Up Inside A Water Heater

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


4. 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

5. Hot Water Is Cloudy Or Has A Metallic Smell & Taste

The water heater’s steel water tank is breaking down.  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.

6. Corrosion, Rust, or Leak At Top Of Water Heater Where Water Pipes Are Connected

7. Water Leaking At Top

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 correct water heater installation.

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

  • 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 without the plastic ring (dielectric union) installed to separate the two metals from touching.

NOTE: The water line may be able to be disconnected and 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.

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

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 explode with the force of a small bomb.  This often damages or distroys the home and can cause injures or kill occupants.

Temperature and pressure relief valves must be be tested once a year to ensure they are working properly.  If it’s not working, the valve must be replaced immediately to ensure your safety.   If the T & P Valve has failed — this is a replaceable part.   This valve is installed entirely for your safety, if it has failed replace it immediately.

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

If it appears we were out to scare you into checking your Temperature & Pressure Relief Valve To Ensure It’s Working — WE ARE!

You Can Test The T&P Valve For Proper Operation:

  • 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

9. 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

Problem #1: Burn marks may indicate improper venting that is causing back-drafting.  This is a venting problem, and does not necessarily mean the water heater must be replaced.

Backdrafting is a serious problem that requires urgent attention.  It indicates exhaust fumes are not exiting your home correctly.  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.

10. Yellow Flame In 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.

Contact Al’s Plumbing For Water Heater Repair or Replacement 

Al’s Sells Only A Premium Water Heater — Rheem Professional Series

Rheem’s Premium Series Water Heater has the word “Professional” on the label near the top


Al’s Plumbing, Heating, and Air Conditioning provides Maintenance, Repair and Replacement Services for all brands of water heaters.  We sell and install only the Rheem Professional Series Water Heater.

Al’s offers Full-Service plumbing.  This includes; clogged toilet repair, water heater repair, water heater replacement for both tankless and tank water heaters, sewer line replacement (under slab or in lawn), trenchless sewer line replacement (in lawn only), slab leak repair, burst pipe repair, repiping, leak detection, water filtration system installation and sales, gas line repair, and gas line installation.

These repairs are only part of what Al’s can do for your plumbing.  We do every type of plumbing repair and replacement — and no job is too big or too small.

Al’s provides Full-Service HVAC System Maintenance, Repair and Replacement Services on all brands of Air Conditioners, Furnaces and Heat Pumps (including Trane and American Standard).  We perform every service needed to keep your heating and air conditioning system running at its best.

We sell and install American Standard, Coleman and Ameristar — Air Conditioner unit, Furnace and Heat Pump.

Contact Al’s today to discuss any problem you have with your Plumbing or HVAC System.  We offer appointments at your convenience & are also your Emergency Plumber resource, with 24/7 Emergency Service.  All our Plumbers are licensed and experienced in diagnosing and repairing your residential plumbing.