How to Flush a Tankless Water Heater
To keep your water heater running efficiently, it’s essential to flush a tankless water heater regularly. Over time, minerals and sediment build up, affecting performance and energy efficiency. To avoid costly repairs, flush a tankless water heater at least once or twice a year.
The process is simple and only takes about an hour. You can flush out any trapped debris using a pump, hoses, and a descaling solution. Doing this once or twice a year can save you from expensive repairs and keep your water heater in shape for years!
Why Flushing Your Tankless Water Heater is Important
Prevents Mineral Buildup
Hard water contains calcium and magnesium minerals that can settle inside your heater. Over time, these deposits can clog the system, reducing water flow and making your heater work harder. Flushing removes buildup and keeps the water moving freely.
Extends the Lifespan of Your Heater
A clogged system forces your heater to overwork, causing unnecessary wear and tear on its components. Keeping it clean reduces strain on the unit and helps it last longer. Regular maintenance can add years to your heater’s life.
Ensures Consistent Water Temperature
If your water temperature fluctuates, mineral buildup might block the heat exchanger. This can lead to lukewarm or inconsistent hot water, frustrating showers, and household tasks. Flushing removes blockages so your heater can maintain a steady temperature.
Improves Energy Efficiency
When your heater is clogged with sediment, it requires more energy to heat water properly. A clean system heats water faster and uses less power, reducing utility bills. Keeping it well-maintained ensures you get the most out of every drop of hot water.
Prevents Unexpected Breakdowns
A neglected water heater can lead to sudden malfunctions, leaving you without hot water when needed most. Flushing helps identify and fix minor issues before they turn into costly repairs. Regular maintenance keeps your heater working smoothly year-round.
Signs Your Tankless Water Heater Needs Flushing
Your tankless water heater should provide a steady flow of hot water, but it can show signs of trouble when minerals build up inside. If you notice any of these issues below, it may be time to flush your system and restore its efficiency.
Fluctuating Water Temperature
If hot water unexpectedly goes from warm to cold, mineral deposits may block the heat exchanger. This makes it harder for your heater to regulate temperature properly, leading to inconsistent water heating.
Reduced Water Pressure
A decrease in water pressure can mean that sediments are clogging the system. When this happens, water struggles to flow freely, affecting performance throughout your home.
Strange Noises
It could be a sign of buildup if you hear gurgling, rumbling, or knocking sounds coming from your heater. These noises happen when mineral deposits interfere with the normal water flow inside the unit.
Error Codes
Most modern tankless water heaters have digital displays that alert you to maintenance needs. Flushing the system is likely the solution if you see an error code related to scaling or water flow issues.
Cloudy or Discolored Water
If your hot water looks murky or has a white tint, it may contain excessive mineral buildup. This affects water quality and indicates that your heater needs cleaning to prevent further damage.
Step-by-Step Guide to Flushing Your Tankless Water Heater
STEP 1: Turn Off Power and Water Supply
Shut off the power to the water heater – electric: turn off the breaker, gas: turn off the gas valve.
Close the cold water inlet and hot water outlet valves to prevent water from flowing during maintenance.
If your heater has a recirculation pump, turn it off as well.
STEP 2: Connect Hoses and Prepare the Solution
Attach one hose to the cold water service valve and connect it to the submersible pump.
Attach the second hose to the hot water service valve and place the other end into a bucket.
Fill the bucket with a descaling solution to break down mineral deposits.
Step 3: Run the Flushing Process
Turn on the submersible pump to flush a tankless water heater, allowing the descaling solution to remove mineral deposits efficiently.
Let it run for 45–60 minutes to clean the internal components thoroughly.
Monitor the solution in the bucket—if it becomes cloudy, it’s dissolving buildup effectively.
Step 4: Rinse the System
Turn off the pump and discard the used descaling solution.
Flush the system by running clean water for another 5–10 minutes to remove any remaining residue.
Disconnect the hoses and close the service valves when done.
Step 5: Restore Power and Test the Heater
Reopen the cold water inlet and hot water outlet valves to allow water to flow normally.
Restore power – turn the breaker back on or relight the gas heater.
Run hot water from a nearby faucet for a few minutes to ensure everything works properly.
How Often Should You Flush Your Tankless Water Heater?
Regular flushing keeps your tankless water heater running efficiently and prevents costly repairs. The ideal flushing schedule depends on your water quality and usage. Here’s a simple guide to help you determine how often to flush your system.
Every 6–12 Months if You Have Hard Water
Hard water contains high levels of minerals like calcium and magnesium, which build up inside your heater over time. If you live in an area with hard water, flushing your system every 6–12 months helps prevent clogs and keeps your water flowing properly. Regular maintenance can also extend the life of your heater.
Once a Year if You Have a Water Softener
A water softener reduces the mineral content in your water, slowing down buildup inside your heater. If your home has a softening system, flushing once a year is usually enough to keep everything clean. Even with soft water, regular maintenance ensures your heater stays efficient.
Check Your Manufacturer’s Recommendations
Each tankless water heater brand has different maintenance guidelines based on design and efficiency. Checking your owner’s manual will help you determine the best flushing schedule for your specific model. Following the manufacturer’s advice ensures your heater performs at its best for years.
Additional Maintenance Tips for a Longer-Lasting Heater
Keeping up with routine maintenance helps your tankless water heater run efficiently for years. Simple steps can prevent damage, improve performance, and reduce the risk of expensive repairs. Here are some key maintenance tasks to keep your heater in top shape.
Clean the Inlet Filter
The inlet filter traps debris and prevents it from clogging the system. Over time, dirt and sediment can build up, restricting water flow and affecting performance. Cleaning the filter regularly ensures smooth operation and prevents unnecessary strain on your heater.
Inspect Vents and Air Intakes
Proper airflow is essential for your heater to work efficiently, especially for gas-powered models. Check the venting and air intake regularly to ensure no blockages or obstructions. A clean ventilation system prevents overheating and helps maintain safe operation.
Check for Leaks
Even small leaks can lead to big problems if left unchecked. Inspect your heater and surrounding pipes for any signs of moisture or dripping water. Catching leaks early can prevent water damage and costly repairs.
Use a Water Softener
If you live in an area with hard water, a water softener can help minimize mineral buildup. This reduces the risk of limescale clogging your system and extends the life of your heater. A softener also improves overall water quality and efficiency.
When to Call a Professional
Regular maintenance can keep your tankless water heater in great shape, but sometimes, professional help is needed. If you notice ongoing issues despite flushing and cleaning, it’s best to call an expert. Here are some signs that it’s time to bring in a professional.
Persistent Error Codes
There could be a deeper issue if your heater displays error messages even after flushing. A technician can diagnose the problem, reset the system, and make necessary repairs. Ignoring error codes may lead to more significant malfunctions down the line.
Severe Mineral Buildup
If you haven’t flushed your heater in years and notice extreme scaling or poor performance, a professional descaling may be required. Technicians have specialized tools and solutions to remove stubborn buildup safely. This ensures your heater runs efficiently without causing internal damage.
Water Leaks or Pressure Issues
Leaks around your heater or a sudden drop in water pressure could indicate damaged components. A professional can inspect for worn-out seals, loose connections, or internal issues. Fixing these early prevents water damage and expensive replacements.
Gas or Electrical Problems
If your heater won’t turn on, has an inconsistent flame, or trips the circuit breaker, don’t try to fix it yourself. Gas and electrical issues can be dangerous and should always be handled by a licensed expert. A professional will ensure your system is safe and functioning correctly.
No Hot Water Despite Maintenance
If your heater still isn’t producing hot water after flushing and cleaning, there may be a mechanical failure. A professional can diagnose problems with the heating element, ignition system, or sensors. Getting expert help ensures your heater is fixed correctly and continues to work efficiently.
Benefits of Professional Flushing
While DIY flushing can help maintain your tankless water heater, a professional service offers deeper cleaning and long-term benefits. Experts use specialized tools and techniques to remove stubborn buildup and ensure your system runs efficiently. Here’s why professional flushing might be the best choice for your heater.
Thorough Descaling
Professionals use industry-grade descaling solutions and equipment to remove tough mineral buildup. This process ensures a deeper clean than standard DIY methods, improving overall performance. A professional flush can help restore water flow and heating efficiency.
Extends the Life of Your Heater
Regular professional maintenance reduces strain on internal components, preventing early wear and tear. Experts can identify and fix potential problems before they lead to costly breakdowns. Investing in professional flushing can add years to your heater’s lifespan.
Detects Hidden Issues
A technician can spot small leaks, worn-out parts, or gas and electrical issues that may go unnoticed during DIY maintenance. Catching these problems early prevents unexpected failures and expensive repairs. Professional inspections help ensure your heater stays safe and reliable.
Saves Time and Effort
Flushing a water heater requires time, effort, and the right tools—especially if there’s heavy buildup. A professional can handle the job quickly and efficiently, saving you the hassle. This allows you to enjoy consistently hot water without the extra work.
Ensures Manufacturer Warranty Compliance
Many tankless water heater manufacturers require professional maintenance to keep the warranty valid. Regular professional flushing helps ensure you stay covered in case of future issues. This can save you money on repairs or replacements if something goes wrong.
Conclusion
To prevent unexpected breakdowns, improve energy efficiency, and extend its lifespan, you should flush a tankless water heater as part of your routine maintenance. Whether you handle it yourself or hire a professional, regularly flushing a tankless water heater will save you time and money in the long run.
These steps will improve energy efficiency and keep your heater working smoothly year-round. Whether you flush it yourself or schedule regular maintenance, keeping your system clean will ensure you always have reliable hot water. Staying proactive with care can make a big difference in performance and savings.
Ready to take action? Grab your supplies and flush a tankless water heater today to keep it in peak condition! If you need expert help, contact Victory Plumbing Services to handle the job.
