How to Flush Tankless Water Heater for Peak Performance

If you want your water heater to last longer and perform more efficiently, one of the best things you can do is flush your tankless water heater regularly. At Clog Heroes in Fredericksburg, VA, we’ve helped countless homeowners keep their plumbing systems in top shape simply by encouraging proper maintenance. In this post, we’ll show you why flushing is necessary, how to do it, and when to call in the pros.

Why You Need to Flush Tankless Water Heater Systems Regularly

Over time, minerals such as calcium and magnesium begin to build up inside your tankless water heater. This is especially common in areas with hard water—like parts of Fredericksburg—where sediment can form much faster than you think. If you don’t flush your tankless water heater regularly, that scale buildup can reduce heating efficiency, cause your system to overwork, and eventually lead to costly repairs or even a full replacement.

According to the U.S. Department of Energy, regular maintenance is essential to keeping tankless water heaters running efficiently and reducing long-term energy costs. Flushing your system helps remove sediment, restore full function, and extend the life of your unit.

How Often Should You Flush Your Water Heater?

So, how often should you flush your tankless water heater? The answer depends on how hard your water is and how much hot water you use. As a general rule of thumb:

• Homes with hard water should flush every 6 months

• Homes with moderate water hardness should flush once per year

• Vacation homes or properties with low water usage may need flushing less often

However, if you notice signs of sediment buildup, it’s best not to wait. Regular flushing is a small investment that can prevent big problems later on.

Signs Your Water Heater Needs to be Flushed

Not sure when it’s time to act? Keep an eye out for these warning signs that you need to flush your tankless water heater soon:

• Reduced hot water pressure: Mineral buildup can block the flow of water through your system.

• Inconsistent water temperatures: If your hot water fluctuates without reason, sediment may be interfering with the heating process.

• Unusual noises: Hearing popping, crackling, or hissing sounds? That’s often caused by scale heating unevenly inside the unit.

• Error codes or warning lights: Some modern tankless water heaters have alerts that indicate maintenance is needed.

If you’re noticing any of these issues, it’s a good idea to flush the system as soon as possible to avoid further damage.

How to Flush Water Heater: A Step-by-Step Guide

Although many homeowners prefer to hire a professional, flushing your tankless water heater can be a manageable DIY task if you’re comfortable handling basic plumbing equipment. Here’s a simplified step-by-step process:

1. Turn off the power and water supply.
   Safety first—cut off the power to the unit (electricity or gas) and shut off the cold and hot water valves.

2. Connect hoses to the service valves.
   Attach one hose to the cold water service valve and the other to the hot water service valve. The cold hose will connect to a pump that recirculates cleaning solution.

3. Add a descaling solution.
   Fill a bucket with white vinegar or a commercial descaling cleaner. Place the submersible pump in the bucket and turn it on to circulate the solution through the heater.

4. Let it flush for about 45 minutes.
   Allow the solution to break down scale and mineral deposits thoroughly.

5. Rinse with clean water.
   Once flushing is complete, run clean water through the system for about 5 minutes to rinse out any remaining solution.

6. Reopen water valves and restore power.
   Reconnect everything, turn the valves back on, and restore power to the system.

Keep in mind: every unit is different, so refer to your manufacturer’s manual for specific instructions or warnings.

What Happens If You Don’t Flush Tankless Water Heater Units?

It might be tempting to skip this chore—especially if your water still seems hot—but skipping flushes can cause big trouble down the road. Failing to flush your tankless water heater leads to:

• Premature system failure

• Decreased energy efficiency

• Increased utility bills

• Clogged pipes and valves

• Voided manufacturer warranties

In other words, regular flushing isn’t just good for your heater—it’s good for your wallet, too.

Can a Professional Do it for You?

Absolutely. If you’re unsure about the process or don’t have the right equipment, a licensed plumber can help. At Clog Heroes, we offer professional tankless water heater maintenance services in Fredericksburg and the surrounding areas. Not only do we flush your system, but we also inspect it for early signs of wear, corrosion, and other issues that might lead to bigger problems.

Hiring a pro ensures everything is done right the first time, saving you time and giving you peace of mind.

How Long Does It Take to Flush Your Water Heater?

The total time to flush a tankless water heater usually falls between 60 and 90 minutes. This includes setup, flushing, rinsing, and restoring the system to its normal operation. While it may take a bit of time upfront, the long-term benefits—like lower energy costs and fewer breakdowns—make it well worth it.

Final Thoughts

If you want reliable hot water year-round and a water heater that lasts for decades, it’s essential to make flushing part of your maintenance routine. By staying ahead of mineral buildup, you’ll avoid expensive repairs, keep your water clean, and enjoy peace of mind.

At Clog Heroes in Fredericksburg, VA, we’re here to help. Whether you want us to flush your tankless water heater for you or just need some expert advice, our team is always ready to serve.