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Guide to the Most Common Tankless Water Heater Problems and its Solutions

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Are you experiencing problems with your tankless water heater? Don’t worry; you’re not alone! Tankless water heaters offer energy efficiency and endless hot water, but they can encounter problems too. In this comprehensive guide, we’ll explore the most common issues tankless water heater owners face and how to troubleshoot them. If you’re unable to fix the problem yourself, you can always contact a qualified water heater repair service in Howell, MI.

Tankless water heaters have revolutionized the way we access hot water, offering energy-efficient and on-demand heating. However, like any appliance, they are not immune to problems. Understanding the potential issues that can arise with tankless water heaters is essential for ensuring that your water heater operates efficiently and lasts for many years.

Common Issues With Tankless Water Heater and Their Solutions

Tankless water heaters offer energy efficiency and endless hot water, but they can encounter problems too. Here are some solutions to common water heater issues to help ensure your water heater operates efficiently and lasts for a long time.

Insufficient Hot Water

If your tankless water heater isn’t producing enough hot water, it could be due to a variety of reasons, such as improper sizing, mineral buildup, or a malfunctioning heating element. One of the most common problems with tankless water heaters is experiencing insufficient hot water. There could be various reasons behind this issue. If the heater is undersized for your household’s hot water demand, it may struggle to keep up, resulting in lukewarm water or abrupt temperature fluctuations. Additionally, mineral buildup inside the heat exchanger can reduce its efficiency and cause the heater to work harder to heat water. Overuse of hot water fixtures simultaneously can also exceed the heater’s capacity, leading to a decrease in water temperature.


To resolve the issue of insufficient hot water, it’s crucial to ensure that your tankless water heater is appropriately sized for your household needs. Consult a professional plumber or HVAC technician to determine the right size for your requirements. Regular maintenance and descaling of the heater can prevent mineral buildup and maintain optimal performance. Consider staggering the use of hot water fixtures during peak demand to ensure a steady supply of hot water.

Fluctuating Water Temperature

Inconsistent water temperature can be frustrating. Issues with the flow rate, a dirty filter, or a faulty temperature sensor may cause this. Experiencing sudden changes in water temperature while using hot water is another common problem with tankless water heaters. Several factors can contribute to this issue, including flow rate problems, a dirty air filter, or a faulty temperature sensor.


Check the flow rate of your water fixtures to ensure that they meet the minimum requirements for your tankless water heater model. Clean or replace the air filter regularly to maintain proper airflow and combustion. If the temperature sensor is malfunctioning, it may need adjustment or replacement. Consider contacting a professional technician to handle any repairs or replacements for precise troubleshooting.

Mineral Buildup and Scaling

Mineral buildup, often caused by hard water, is a common problem for tankless water heaters. Over time, minerals such as calcium and magnesium can accumulate inside the heat exchanger, reducing its efficiency and potentially leading to long-term damage.


Routine descaling of your tankless water heater is essential to remove mineral buildup and ensure optimal performance. Consider using a water softener or installing a water softening system for your home to reduce the impact of hard water on the heater. Regular maintenance and descaling will prolong the life of your tankless water heater and maintain its efficiency.

Ignition Problems (Gas Heaters)

Gas-powered tankless water heaters rely on proper ignition to function effectively. Ignition issues can occur due to various reasons, including gas supply problems or a dirty burner/igniter.


Ensure that the gas supply to the water heater is adequate and the gas valve is fully open. Clean the burner and igniter regularly to prevent any dirt or debris from hindering the ignition process. If the problem persists, contact a professional technician to inspect and address the underlying issue.

Electrical Glitches (Electric Heaters)

water heater upgrade

Electric tankless water heaters can encounter electrical issues that may disrupt their operation.


If your electric tankless water heater experiences electrical glitches, check the circuit breaker to see if it has tripped. Overloaded circuits or other electrical problems can cause the circuit breaker to trip, cutting off power to the heater. Address any electrical issues promptly and consult an electrician if necessary to resolve the problem.

Excessive Noise

Unusual noises coming from your tankless water heater can be concerning. Rattling or banging sounds may indicate mineral buildup or loose/damaged components.


Regular descaling and maintenance can help prevent mineral buildup and reduce noise. Tighten any loose fittings and inspect the heater for signs of damaged components. If you are unsure about troubleshooting, seek the help of a professional technician to address the noise issue.


Water leaks can occur in the water supply lines, valves, or within the tankless water heater unit.


Regularly inspect all water connections and tighten any loose fittings to prevent leakage. If you detect a leak within the heater, contact a professional technician immediately to avoid water damage and resolve the issue.

Don’t let common problems with tankless water heaters dampen your spirits. Stay informed, address issues promptly, and enjoy the benefits of endless hot water in your home. Contact Brock Mechanical for more information and expert solutions to your tankless water heater problems.

Keep Your Tankless Water Heater Running Smoothly

Tankless water heaters offer numerous benefits, but they can encounter problems over time. To ensure their efficient and reliable operation, it’s essential to address any issues promptly and perform regular maintenance. Professional inspection and troubleshooting are highly recommended for complex problems or if you are uncertain about handling repairs yourself. With proper care and attention, your tankless water heater will continue to provide endless hot water for your household’s needs for years to come.

If you encounter any of these issues, it’s crucial to contact a professional plumber or HVAC technician like Brock Mechanical for expert assistance. Regular maintenance and descaling are key to preventing problems and ensuring the longevity of your tankless water heater. With proper care, your tankless water heater will continue to provide efficient and reliable hot water for years to come.

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