Water heaters are often out of sight and out of mind until they stop working. Understanding why these appliances fail can help you prevent unexpected breakdowns and costly water damage. In the video above, plumbing and heating expert Richard Trethewey provides an eye-opening look at the inner workings of a water heater, revealing some common causes of failure and how you can help extend your tank’s lifespan.
Parts of a Water Heater
The typical water heater in American homes is a gas-fired tank model. While it may look simple from the outside, the interior components are complex and prone to wear over time.
Anode Rod
A central component of the water heater is the anode rod. This rod corrodes before the tank does, sacrificing itself to protect the steel. When functioning correctly, it can significantly extend the life of the water heater. Routine inspection and replacement of the anode rod help maintain this line of protection.
Heating Elements and Controls
Gas-fired water heaters use a burner at the bottom of the tank. A series of controls regulate the temperature and pressure. These controls include thermostats, thermocouples, and pressure relief valves, all working together to maintain peak water heating conditions and prevent potential hazards.
Steel Tank With Glass Lining
At its core, a water heater is a steel tank with glass lining. This design aims to keep the water separate from the steel, preventing rust and corrosion. But the glass lining isn’t immune to damage. Over time, tiny cracks and fissures can develop. These allow water to contact the steel and begin the rusting process.
Top Reasons for Water Heater Failure
Understanding why water heaters fail can help homeowners take preventive measures and recognize when it’s time for a replacement:
1. Corrosion and Rust
The most common cause of water heater failure is corrosion. Despite the glass lining, water eventually finds its way to the steel tank. When this happens, rust begins to form, weakening the tank’s structure. In the video, Trethewey points out visible rust around the flue passageway and water outlet fittings, which are clear indicators of internal corrosion. Regular checks for rust can help identify issues before they become severe.
2. Sediment Buildup
Over time, minerals in the water settle at the tank’s bottom. This sediment buildup can:
- Cause strange noises as the water heater operates
- Create hot spots on gas-fired models
- Lead to premature tank failure
- Reduce heating efficiency
Regular flushing of the tank can mitigate sediment buildup and extend the heater’s lifespan.
3. Anode Rod Depletion
Once the anode rod is fully depleted, the tank becomes vulnerable. Trethewey explains this by showing a severely corroded anode rod. Homeowners should check the anode rod regularly and replace it if it’s significantly corroded to protect the tank.
4. Pressure and Temperature Issues
Excessive pressure or temperature can cause the tank to expand and contract, leading to metal fatigue and eventual failure. Faulty temperature and pressure relief valves can worsen these issues. Make sure that the water heater’s pressure and temperature settings are within safe limits to prevent stress on the tank.
5. Poor Water Quality
Water quality itself influences the lifespan of a water heater. Hard water, which contains high levels of minerals, can speed sediment buildup and corrosion. Installing a water softener can help improve water quality and extend the life of the water heater.
Signs of a Failing Water Heater
Recognizing the signs of a failing water heater can help you prevent unexpected breakdowns and water damage. Watch out for the following:
- Visible rust and leaks: Rust around the water inlet and outlet connections or at the base of the tank often indicates internal corrosion. Small leaks can quickly turn into major problems, so address them promptly. Regularly inspecting these areas for signs of rust or leaks can help catch problems early.
- Inconsistent water temperature: If your water heater struggles to maintain a consistent temperature or doesn’t produce enough hot water, it may be nearing the end of its lifespan. Fluctuating water temperatures can indicate issues with the heating elements or sediment buildup affecting the tank’s efficiency.
- Strange noises: Popping, crackling, or rumbling sounds often indicate sediment buildup at the bottom of the tank. This can lead to overheating and damage to the tank lining, as the debris interferes with the heat transfer, causing the metal to overheat.
- Age of the unit: Most water heaters last between 8 and 12 years. If your unit is approaching or exceeding this age range, it’s wise to start planning for a replacement. Aging water heaters are more likely to experience failures and may not operate as efficiently as newer models.
Extending the Life of Your Water Heater
Here are steps you can take to maximize your water heater’s lifespan.
Controlling Water Temperature
Setting your water heater to a lower temperature (around 120 degrees Fahrenheit) can reduce wear on the tank and components while saving energy. Lower temperatures extend the life of the water heater, help prevent scalding, and reduce energy bills.
Regular Maintenance
Performing annual maintenance can significantly extend the life of your water heater. This includes:
- Flushing the tank to remove sediment
- Inspecting valves and connections for leaks
- Checking if the anode rod needs replacing
- Testing the pressure relief valve
Installing a Water Softener
If you live in an area with hard water, install a water softener to reduce mineral buildup. This can help prevent sediment accumulation and protect the internal components of the water heater from damage.
Insulating the Tank and Pipes
Adding insulation to your water heater tank and pipes can improve efficiency and reduce heat loss. This can lower energy consumption and reduce the workload on the water heater, helping it last longer.
Replacing the Anode Rod
As Trethewey emphasizes, replacing the anode rod every 3–5 years could double the life of your water heater. This simple maintenance task is often overlooked but can save homeowners significant money in the long run. Keeping the anode rod in good condition helps the tank remain protected from corrosive elements.
When To Replace Your Water Heater
Knowing when to replace your water heater can save you from unexpected failures and potential water damage.
- Age: If your water heater is over 10 years old, it’s wise to start planning for a replacement—even if it’s still functioning. As Trethewey notes, expecting 10–12 years from a water heater is reasonable, but some units can last up to 20 years with proper maintenance. Regularly checking the condition of your water heater helps you determine the right time for a replacement.
- Cost of repairs versus replacement: When faced with a major repair on an older unit, consider the cost of the repair versus the price of a new and more efficient water heater. Often, replacement is the cheaper choice in the long run. Weighing the benefits of a new unit’s efficiency and reliability against the repair costs of an old one can guide your decision.
- Efficiency upgrades: Newer water heaters are significantly more efficient than older models. Upgrading to a high-efficiency unit can lead to substantial energy savings over time. Look for water heaters with advanced features, such as better insulation, higher energy factor ratings, and smart controls that optimize performance.
- Environmental concerns: Upgrading to a more efficient water heater not only saves money but also reduces your environmental footprint. Newer models typically use less energy and produce fewer emissions, contributing to a greener home. Choosing an energy-efficient water heater can be a responsible choice for your wallet and the planet.