How to Fix Tankless Hot Water Heater

Are you having trouble with your tankless water heater? Is it not heating up the water as it should or is it making strange noises? Don’t worry. This guide will provide you with some simple steps on how to fix tankless hot water heater.

Tankless hot water heaters are a convenient and energy-efficient way to ensure a steady supply of hot water in your home. However, like any appliance, they can encounter issues that may disrupt their performance over time. Common problems include insufficient hot water, mineral buildup, or system error codes. Understanding how to troubleshoot and fix these issues can save you both time and money while prolonging the lifespan of your unit.

This guide will walk you through the essential steps to identify and resolve common problems with your tankless hot water heater, helping you easily restore its functionality.

What Are the Causes of Tankless Hot Water Heater Problems?

Before we dive into the steps to fix these issues, let’s take a quick look at some potential causes that may lead to problems with your tankless hot water heater.

1. Insufficient Flow Rate: If your tankless hot water heater is not producing enough hot water, it could be due to low flow rates caused by partially closed valves or undersized pipes.
2. Mineral Buildup: Due to hard water, minerals can accumulate in the heating elements of your tankless hot water heater, reducing its efficiency and causing performance issues such as decreased flow rate or even complete failure.
3. System Error Codes: Most modern tankless water heaters have built-in error code systems that identify potential issues and display them on the unit’s control panel. These codes can range from minor problems like dirty air filters to more severe issues like ignition failures.

These are just a few potential causes of tankless hot water heater problems. Now, let’s move on to the steps you can take to troubleshoot and fix these issues.

What Will You Need?

To fix your tankless water heater, you will need a few tools and materials. These include:

• A screwdriver set
• A voltmeter
• A descaling solution or vinegar
• A hose
• Protective gear (gloves, safety glasses)

You may also need replacement parts depending on the specific issue with your tankless water heater.

8 Easy Steps on How to Fix Tankless Hot Water Heater

Step 1: Turn Off the Power and Water Supply 

Before beginning any maintenance or repair work, turning off the power and water supply to the tankless water heater is crucial. For electric units, locate the circuit breaker and switch it to the “off” position to cut off the electricity. For gas-powered units, turn off the gas valve to ensure safety. Similarly, close the water supply valve to prevent water from flowing into the unit during repair. These precautions are essential to avoid electrical shocks, water leaks, or other safety hazards while working on the system. Always double-check to confirm the power and water supplies have been fully shut off before proceeding to the next steps.

Step 2: Drain the Heater 

Once the power and water supply have been turned off, the next step is to drain the tankless water heater. Locate the purge valves on the unit, typically marked with red and blue caps for hot and cold water lines. Attach hoses to both valves and direct them into a bucket or a suitable drainage area. Open the purge valves to allow any remaining water in the system to flow out. This step is crucial for preventing leaks and ensuring the unit is empty before performing maintenance or repairs. Remember to wear protective gear as the water may still be hot.

Step 3: Clean the Filter 

After draining the tankless water heater, the next step is to clean the system’s filter. Locate the filter, which is usually positioned near the cold water inlet. Carefully remove it using the appropriate tools, and wash away any debris or mineral buildup under running water. If the filter is excessively clogged or damaged, consider replacing it with a new one. Ensuring the filter is clean helps maintain optimal water flow and prevents potential damage to the unit. Once the filter is clean and dry, reinstall it securely before moving on to the next step.

Step 4: Flush the System 

You will need to perform a system flush to remove any mineral deposits or scale buildup inside the tankless water heater. Connect the hoses to the service ports located on the inlet and outlet valves. A suitable flushing solution, typically white vinegar or a descaling agent approved by the manufacturer, is circulated through the unit with the help of a submersible pump. Allow the solution to flow through the system for 45 minutes to an hour, as this helps dissolve and clear out buildup that can hinder performance. Once the flushing is complete, disconnect the hoses and flush out the system with clean water to remove any remaining solution. This process keeps the heater functioning efficiently and prolongs its lifespan.

Step 5: Inspect and Reassemble the Unit 

After flushing the system, inspect the tankless water heater for any visible signs of wear, corrosion, or damage. Check the connections, valves, and fittings to ensure they are secure and in good condition. Replace any damaged components with the manufacturer’s guidelines if you notice any damaged components. Once the inspection is complete, reassemble the unit by reconnecting all parts and ensuring everything is securely in place. Turn on the water and power supply, and test the heater to ensure it functions correctly. This step ensures the unit is safe and ready for optimal performance.

Step 6: Perform Regular Maintenance 

Establish a routine maintenance schedule to keep your tankless water heater functioning at peak efficiency. Regular tasks should include cleaning the inlet filter to prevent debris from clogging the system, checking for leaks or unusual noises, and ensuring proper ventilation around the unit. Additionally, consider scheduling a professional inspection annually for a more thorough check-up of internal components. Following these maintenance practices can help extend the water heater’s lifespan and prevent unexpected issues.

Step 7: Troubleshooting Common Issues 

Even with proper maintenance, occasional issues may arise with your tankless water heater. If you experience a lack of hot water, check for fundamental problems such as low water pressure, tripped circuit breakers, or a closed gas valve. For inconsistent water temperatures, ensure the water flow meets the unit’s minimum flow requirement and inspect for potential blockages in the system. If error codes appear on the unit, consult the user manual for specific troubleshooting guidance. Addressing these common problems promptly can minimize downtime and ensure continuous efficiency.

Step 8: Upgrading or Replacing Your Water Heater 

Consider an upgrade or replacement if your tankless water heater frequently malfunctions or can no longer meet your household’s needs. Advances in water heater technology have led to more energy-efficient models with improved features, such as remote operation and better flow rate capacity. When upgrading, assess your household’s hot water demands to select the appropriate size and model. Hiring a licensed professional to install the new unit also ensures it is set up correctly for optimal performance. Investing in a modern tankless water heater can enhance efficiency and provide long-term cost savings.

Following these steps and practicing routine maintenance ensures your tankless water heater is operating at peak efficiency.

5 Things You Should Avoid

1. Skipping the Manufacturer’s Manual: Avoid bypassing the instructions provided in the manufacturer’s manual. This guide is tailored specifically for your model and contains crucial troubleshooting tips and safety measures.
2. Ignoring Regular Maintenance: Failing routine maintenance can lead to sediment build-up or clogging in your tankless water heater. Always check for signs of wear and perform necessary cleaning as recommended.
3. Using Incorrect Tools: Avoid using improper tools when attempting any DIY repairs. Doing so can damage components or worsen the issue, potentially leading to costly repairs or replacements.
4. Tampering With Electrical Components Without Proper Knowledge: Never attempt to fix electrical or gas components if unsure about their operation. This can be dangerous and should be left to a licensed professional.
5. Neglecting to Shut Off Power and Water Supply: Before starting any repair work, always turn off your unit’s power and water supply. Neglecting this step can result in serious accidents or further damage to the heater.

By avoiding these common mistakes, you can maintain the longevity and functionality of your tankless water heater.

Conclusion

How to fix tankless hot water heater requires a methodical and safety-conscious approach. Always start by identifying the issue through proper troubleshooting and consult the user manual for guidance.

Regular maintenance, such as descaling and cleaning filters, can prevent many common problems and extend the life of your unit. Remember to prioritize safety by shutting off the power and water supply before performing any repairs. For complex issues, particularly those involving electrical or gas components, seek the assistance of a licensed professional to avoid risks and ensure a proper fix.

By taking these precautions and staying informed, you can efficiently address issues with your tankless water heater and maintain its performance over time.