As an experienced water heater specialist, I’ve seen firsthand the challenges that homeowners and plumbers face when dealing with mineral scale buildup in electric tankless water heaters. In our 10 years of water heater experience… This issue can significantly impact the efficiency, lifespan, and performance of these innovative appliances. In this comprehensive article, we’ll explore the causes of mineral scale, its effects on tankless water heaters, and proven methods for preventing this common problem.
Understanding Mineral Scale Buildup
Mineral scale, a common issue in many water heater systems, is the result of dissolved minerals in the water, such as calcium and magnesium, precipitating out and adhering to the surfaces of the water heater’s components. This is especially problematic in electric tankless water heaters, where the water is rapidly heated using high-powered heating elements.
As the water passes through the heat exchanger coils, the rapid temperature rise causes the dissolved minerals to crystallize and stick to the coil surfaces. Over time, this mineral scale can build up, creating an insulating layer that reduces the heat transfer efficiency of the coils. This, in turn, leads to higher energy consumption, decreased hot water output, and potentially even premature failure of the water heater.
The Risks of Mineral Scale Buildup
The consequences of mineral scale buildup in an electric tankless water heater can be quite severe. Let’s take a closer look at the key issues that can arise:
Decreased Efficiency: The insulating layer of mineral scale on the heat exchanger coils impedes the transfer of heat from the heating elements to the water. This reduces the overall efficiency of the water heater, leading to higher energy bills and increased operating costs.
Reduced Hot Water Output: As the mineral scale builds up, it restricts the flow of water through the heat exchanger, reducing the amount of hot water that the tankless unit can produce. This can be especially problematic during high-demand periods when multiple fixtures are in use simultaneously.
Premature Failure: Extensive mineral scale buildup can cause the heating elements to overheat, leading to premature failure of the water heater. In severe cases, the scale can even cause the heat exchanger coils to rupture, resulting in a costly and inconvenient replacement.
Increased Maintenance: Regular maintenance, such as flushing the system and descaling the heat exchanger, becomes more frequent and time-consuming when dealing with excessive mineral scale buildup. This can add to the overall cost of owning and operating the water heater.
Preventing Mineral Scale Buildup
Fortunately, there are several effective strategies and technologies available to help prevent mineral scale buildup in electric tankless water heaters. Let’s explore some of the best practices:
Water Softening and Filtration
One of the most effective ways to combat mineral scale is to address the water quality before it enters the tankless water heater. Installing a whole-home water softener or a water filtration system can significantly reduce the concentration of dissolved minerals, such as calcium and magnesium, in the water supply. This, in turn, reduces the amount of scale that can form on the heat exchanger coils.
When selecting a water softener or filter, it’s important to choose a system that is compatible with the flow rate and water usage of your tankless water heater. Consulting with a reputable plumber or water treatment specialist can help you determine the right solution for your specific needs.
Scale Prevention Additives
In addition to water softening and filtration, there are specialized scale prevention additives that can be used to inhibit mineral scale formation in electric tankless water heaters. These additives, such as Scale TAC-ler Plus from Stiebel Eltron, work by altering the crystallization process of the minerals, causing them to form microscopic, suspended crystals instead of adhering to the heat exchanger surfaces.
These scale prevention additives are typically installed on the cold water inlet of the tankless water heater, where they can treat the water before it enters the system. They are easy to install, require minimal maintenance, and can be an effective solution for homeowners with moderately hard water.
Periodic Flushing and Descaling
Even with water softening and scale prevention additives, it’s important to regularly flush and descale the electric tankless water heater to remove any existing mineral buildup. This process typically involves circulating a descaling solution through the system, which helps to dissolve and flush out the scale deposits.
Many tankless water heater manufacturers, such as Stiebel Eltron, offer descaling kits and solutions designed specifically for their products. These kits often include a submersible pump, hoses, and a biodegradable descaling fluid, making the process relatively straightforward for homeowners or plumbers to perform.
Depending on the water quality and usage patterns, it’s generally recommended to flush and descale an electric tankless water heater every 12-18 months to maintain optimal performance and efficiency.
Selecting the Right Water Heater
When choosing an electric tankless water heater, it’s essential to consider the water quality in your area and select a model that is well-suited to handle any potential mineral scale issues. Some tankless water heater manufacturers offer models with enhanced scale-resistant features, such as specialized heating elements or advanced water treatment systems.
By doing your research and selecting a tankless water heater that is designed to mitigate mineral scale buildup, you can help double-check that the long-term reliability and efficiency of your system.
Addressing Existing Mineral Scale Buildup
If you have an electric tankless water heater that is already suffering from significant mineral scale buildup, there are steps you can take to restore its performance:
Descaling: As mentioned earlier, a thorough descaling of the heat exchanger coils using a dedicated descaling solution can help remove existing scale deposits and improve the water heater’s efficiency.
Heat Exchanger Replacement: In extreme cases, where the mineral scale buildup is too extensive to be fully removed through descaling, the heat exchanger coils may need to be replaced. This is a more involved and costly repair, but it can effectively restore the water heater’s performance and prevent future issues.
Water Treatment Upgrades: If the water quality in your home is the root cause of the mineral scale buildup, consider upgrading your water softening or filtration system to provide better protection for your tankless water heater.
By addressing existing mineral scale issues and implementing preventative measures, you can double-check that that your electric tankless water heater continues to operate at peak efficiency for years to come.
Conclusion
Preventing mineral scale buildup in electric tankless water heaters is crucial for maintaining their performance, efficiency, and longevity. By understanding the causes and risks of this common problem, and implementing effective strategies like water softening, scale prevention additives, and regular flushing and descaling, you can keep your tankless water heater running smoothly and minimize the need for costly repairs.
If you’re in the market for a new electric tankless water heater or need assistance with maintaining your existing system, be sure to visit WaterHeaterPick.com for more expert insights and guidance. Our team of experienced water heater specialists is dedicated to helping you make the best choices for your home’s hot water needs.
Tip: Flush your water heater tank at least once per year
