A leaking water heater can cause significant damage, especially if it is located in a finished area of your home. To avoid a costly disaster, it’s important to monitor the age of your water heater and watch for signs of wear or deterioration. In this article, we’ll discuss the most common warning signs that your water heater may be failing, how to extend its lifespan, and what you can do to prevent or minimize damage in the event of a leak.
Average Lifespans Of Water Heaters
The lifespan of a water heater depends on several factors, including the type of unit, water quality, and usage habits. While the average lifespan isn’t an exact science, knowing these general timelines can help you determine when to perform preventative maintenance, make repairs, or consider a replacement.
- Gas-powered tank-type water heaters (natural gas or propane) typically last 5 to 10 years.
- Electric tank-type water heaters usually last 10 to 15 years.
- Tankless water heaters have a longer lifespan, averaging 10 to 20 years.
- Indirect water heaters, which use a home’s boiler for heat, can last 20 years or more.
Discolored Water
Discolored hot water is often an early warning sign that your water heater is rusting internally and may be nearing the end of its life. This is especially true if only the hot water is discolored, which typically indicates corrosion inside the tank. While discoloration can be hard to notice while water is running, it becomes more apparent when you fill a clear glass or white bowl.
Although this rust-colored water is usually not a health hazard, it does suggest that the tank could soon fail or begin to leak. If both hot and cold water are discolored, the issue is more likely to be with your home’s plumbing or water supply, not the water heater itself.
It’s important to note that water discoloration doesn’t always occur as a water heater ages, but it remains a quick and simple indicator of tank health. This problem is most common with tank-style water heaters, which typically have steel tanks lined with protective materials that degrade over time. Once these protective layers break down, the steel begins to corrode.
In contrast, indirect and tankless water heaters are usually made of stainless steel, a corrosion-resistant alloy. While more durable, stainless steel units are significantly more expensive and are generally used in high-demand applications or when longevity is a priority.
Unusual Noises
Water heaters are generally quiet during operation, aside from the sound of the burner in direct-fired models. If you start hearing unusual noises like popping, crackling, or kettling, it’s often a sign of excessive mineral buildup or rust inside the tank.
These deposits can trap air or create insulation between hot spots and cooler water, leading to significant temperature differences within the tank. This uneven heating causes the water to expand rapidly, resulting in the strange noises you’re hearing.
In some cases, these sounds may also indicate that the tank structure is weakening. As internal pressure increases, the tank walls may begin to flex or deform slightly, producing crinkling or popping noises.
If you live in an area with hard water, these noises may suggest it’s time to flush the tank to remove mineral buildup. In areas with softer water, the sounds are more likely linked to corrosion rather than scale, which could be a warning sign that the tank is nearing the end of its service life.
Temperature Changes And Flow Rate Reductions
As a water heater ages, its temperature sensor, responsible for monitoring and regulating water temperature, can become corroded, coated in scale, or buried in sediment. These issues reduce the sensor’s ability to accurately detect temperature, leading to inconsistent or overly hot water.
Although the temperature sensor isn’t part of the tank structure itself, its degradation often reflects the overall condition of the water heater. In other words, when the sensor is in poor shape, the tank usually is too.
Increased sediment or mineral buildup inside the tank or on the heating elements can also slow heat transfer, resulting in reduced hot water output. You may notice you can’t take as long of a shower, or that you can no longer run multiple hot water fixtures at once. In areas with hard water, flushing the tank may resolve these issues by removing mineral deposits. In areas with soft water, similar symptoms often indicate internal rust and tank deterioration, suggesting the unit may need to be replaced.
Tankless water heaters can experience similar problems. If scale builds up in the heat exchanger, it can block heat transfer and trigger the unit to restrict water flow. This slowdown allows the water to reach the desired temperature before exiting the unit. In many cases, flushing the heat exchanger with a descaling solution (such as vinegar or a manufacturer-recommended cleaner) can restore proper performance.
Increased Energy Consumption
While it can be hard to pinpoint, an unexpected increase in utility bills may be a sign that your water heater is becoming less efficient, or even starting to fail. As scale or sediment builds up in the tank or on heating coils, the unit must work harder and longer to heat the same amount of water. This results in higher consumption of gas, electricity, or oil, depending on your system.
To spot this issue early, try comparing your monthly and yearly utility bills, while accounting for changes in weather and usage. A consistent upward trend, especially when your heating or cooling needs haven’t changed, could point to a water heater losing efficiency.
Repeated Pilot Failures
Many tank-type water heaters still rely on a standing pilot light and thermocouple to operate. If your pilot light goes out periodically but can be relit, it may indicate a hidden problem, possibly even a leaking tank.
In some cases, a water heater may only leak when the water is hot and internal pressure increases. If that leak occurs above the pilot, water can drip down, extinguish the flame, and then stop leaking as the tank cools, making it difficult to detect, especially if no water reaches the floor.
However, a leaking tank isn’t the only reason a pilot light might go out. You should also check the thermocouple, which may be failing, and inspect the chimney draft to ensure proper ventilation. While a malfunctioning thermocouple issue will be rectified with the change of the water heater, a poor draft will continue to cause problems even with a new water heater. Poor draft can lead to carbon monoxide backdrafting into the home, creating a serious health and safety hazard. If you’re experiencing repeated pilot outages, it’s critical to check for both equipment failure and ventilation problems before assuming a simple fix.
Physical Inspection Of The Water Heater
While water heaters are often encased in insulation, making it difficult to inspect the tank directly, you can still check the plumbing connections and surrounding area for signs of wear or failure.
Corrosion at Connections:
Connections to the water supply or heating loop are particularly prone to corrosion, especially where dissimilar metals (like copper and steel) meet. Although dielectric unions or brass fittings are used to reduce galvanic corrosion, they aren’t foolproof. If you notice discoloration, corrosion, or buildup around these fittings, it may be time to replace the connections or, depending on the age and condition of the unit, the entire water heater.
Signs of Leaks or Moisture:
Any visible moisture around the base of the unit can be a warning sign. While some condensation can form on cold pipes due to temperature differences, it’s usually minimal and shouldn’t form large puddles. Persistent moisture could indicate a leaking tank.
For tankless water heaters, be aware that the condensate pump can fail, allowing collected condensate to spill onto the floor. This can look like a leak but is usually isolated to the area near the pump, not the unit itself. Regardless of the source, if you detect water near your heater, monitor it closely to determine whether it’s from the unit or from external factors.
Excessive Heat Output:
Another red flag is excessive heat radiating from the unit. This may mean that scale buildup inside the tank or coil is slowing heat transfer, forcing the burner to run longer and overheat the system. It could also be a sign of a venting or flue issue, where combustion gases aren’t being properly vented. In addition to reducing efficiency, this creates a dangerous safety risk, as carbon monoxide can accumulate in the space.
Preventative Maintenance
Preventative maintenance depends on the type of water heater you have. Tank-type water heaters are made of steel protected by a glass lining and typically fail when water exposure compromises this lining. To extend the tank’s life, these heaters include a sacrificial anode rod, usually made of magnesium or zinc. These metals corrode first, protecting the steel tank from rusting. Replacing the anode rod periodically can significantly prolong the tank’s lifespan. More recently, electric anode rods have become available; they produce a small electric charge that pulses to provide extra electrons and prevent corrosion at a molecular level. Made from corrosion-resistant materials, these electric anodes don’t require replacement. While the science behind them is sound, there is limited real-world data on their long-term effectiveness. In areas with hard water, flushing tank-type heaters periodically helps remove mineral buildup at the tank’s base, improving efficiency and extending service life. Tankless water heaters should have their coils flushed every one to two years to remove scale buildup, which develops naturally during operation. This descaling improves heat transfer, increasing efficiency and reducing wear by allowing the unit to operate at lower temperatures. Indirect water heaters typically require little preventative maintenance, as they are made entirely of stainless steel and their design prevents scale buildup.
Leak Mitigation
If your water heater is located in a finished space, it might be worth investing in a leak mitigation product. The simplest form is a safe waste pan. These pans go under the water heater and have a drain that allows collected water to move away from the water heater and into a drain or sump pump to minimize or prevent water damage. It can be taken a step further with the addition of an automatic water shutoff device. These devices come with a sensor that goes in the pan and a motorized shutoff valve that is installed on the water supply for the water heater. When water is detected, an alarm is sounded and the valve is turned off to prevent new water from entering the water heater. These systems are manually resettable in the case of accidental activation, and can be reused with the future water heaters. These systems do require an outlet to operate, but can significantly reduce or prevent water damage especially in finished basements where leaks may go undetected for a period of time.
Final Thoughts
While most of these warning signs are more common in tank-type water heaters due to their steel construction, even stainless steel models can exhibit similar issues. Paying attention to these signs can help you avoid costly repairs and prevent flooding caused by a failed water heater. If your water heater is nearing the end of its lifespan or needs servicing, we’re here to help with expert advice, maintenance, and replacement services. Contact us at (508) 233-2382 or through the form on our website.