How Hard Water Affects Your Tankless Water Heater and What to Do About It

Tankless water heaters are an excellent choice for homeowners looking for energy efficiency and continuous hot water. However, if your home has hard water, your system could be at risk of mineral buildup, reduced efficiency, and long-term damage. Understanding the effects on your tankless water heater and how to prevent potential issues is essential to keeping your system running smoothly for years to come.

What Is Hard Water?

Hard water contains high levels of minerals like calcium and magnesium. While these minerals aren’t harmful to your health, they can create serious issues for plumbing systems and appliances, including your tankless water heater. Over time, hard water leads to limescale buildup, affecting your water heater’s efficiency and overall performance.

How This Affects Your Tankless Water Heater

Mineral Buildup in the Heat Exchanger
- A tankless water heater relies on a heat exchanger to warm the water as it flows through the system. When hard water is heated, calcium and magnesium separate from the water and form limescale deposits on the internal components.
- These deposits act as an insulator, making it harder for your system to transfer heat effectively. This means your unit has to work harder, use more energy, and heat water less efficiently.
Reduced Water Flow & Clogs
- Limescale doesn’t just stay inside the heat exchanger—it can accumulate inside water lines and plumbing, leading to clogs and restricted water flow.
- If your water pressure has dropped, or you’re experiencing inconsistent water temperatures, hard water buildup could be the culprit.
Higher Energy Bills
- As limescale builds up, your tankless water heater needs more energy to heat water, leading to higher utility bills.
- In severe cases, the strain on the system can cause premature failure, leading to expensive repairs or even full unit replacements.
Shortened Lifespan
- Hard water can significantly reduce the lifespan of your tankless water heater.
- If not properly maintained, mineral deposits can cause components to overheat and wear out faster, forcing you to replace your unit sooner than expected.

How to Protect Your Tankless Water Heater

Regular Descaling & Flushing
- Routine flushing and descaling remove mineral deposits and prevent limescale from restricting performance.
- It’s recommended that homeowners flush their system at least once a year—or more frequently in areas with extremely hard water.
Install a Water Softener
- A water softener can drastically reduce the impact of hard water by removing excess calcium and magnesium before it reaches your tankless system.
- Softened water helps prevent scale buildup, prolongs the lifespan of your water heater, and improves overall plumbing health.
Use a Scale Inhibitor System
- A scale inhibitor filter can be installed before your tankless water heater to minimize mineral accumulation.
- These systems are cost-effective and easy to maintain, providing additional protection against limescale.
Schedule Professional Maintenance
- Regular maintenance by a professional ensures your system stays clean, efficient, and free from mineral buildup.
- ProTech offers comprehensive descaling and maintenance services, so you don’t have to worry about hard water damaging your unit.

Keep Your Tankless Water Heater Running Smoothly with ProTech

Hard water can take a toll on your tankless water heater, but with proper maintenance, descaling, and preventative solutions, you can keep your system working efficiently for years.

At ProTech Tankless, we specialize in professional descaling, water heater maintenance, and protective solutions to help homeowners combat the effects of hard water. Whether you need a system flush, a water softener installation, or expert advice, we’re here to help!

Contact ProTech today to schedule a maintenance check and keep your tankless water heater running at peak performance!