How Often Should I Have My Tankless Water Heater Flushed?

If you’re asking yourself, “how often should I have my tankless water heater flushed?”, you’re already ahead of the game. Most people don’t think about water heater maintenance until the day they turn on the tap and—surprise—the hot water runs cold. The good news? A little routine care goes a long way in keeping your tankless system efficient, reliable, and long-lasting.

At Clog Heroes Plumbing, Sewer & Drain, we’ve worked on more water heaters than we can count (some in perfect shape, others… not so much). Let’s break down what flushing does, how often to schedule it, and why it matters more than you might think.

Why Flushing Your Tankless Water Heater Matters

Tankless water heaters don’t store hot water like traditional tanks. Instead, they heat water on demand. Sounds efficient, right? It is—but there’s a catch. Minerals in the water, especially calcium and magnesium, can build up inside the heat exchanger.

Over time, that buildup restricts water flow, reduces efficiency, and can even damage your system. (Think of it like cholesterol in your arteries—except instead of a doctor, you need a plumber.) Regular flushing clears out these deposits and keeps your system working like new.

For more technical details, the U.S. Department of Energy notes how maintenance directly impacts the lifespan of water heaters.

So, How Often Should I Have My Tankless Water Heater Flushed?

Here’s the answer most homeowners are really after: at least once a year. That’s the general rule of thumb. However, if you live in an area with hard water—or you notice reduced water flow—it’s smart to schedule flushing every six months. Learn more about our tankless water heater services and how regular care prevents early breakdowns.

Why the difference? Hard water (like we have here in Fredericksburg) contains more minerals, and those minerals love to settle in your tankless water heater. Even with a water softener, buildup can still happen faster than you’d expect.

I like to tell customers: if your shower pressure feels weaker or your tankless water heater sounds like it’s working harder than usual, it’s probably time for a flush.

Signs It’s Time for a Flush

If you’re still wondering, “how often should I have my tankless water heater flushed,” look out for these telltale signs:

• Reduced hot water flow (that shower feels weaker)

• Fluctuating water temperature (hello, mid-shampoo cold blast)

• Strange noises (a tankless heater shouldn’t sound like popcorn popping)

• Higher energy bills without obvious reasons

Catching these issues early can prevent expensive repairs down the road.

What Happens During a Tankless Water Heater Flush?

Flushing sounds fancy, but it’s really just giving your system a deep clean. Here’s what we do:

1. Turn off the unit and disconnect the power and water supply.

2. Attach hoses to the service ports.

3. Circulate a descaling solution—usually vinegar or a professional cleaner—through the system for about 45 minutes.

4. Rinse everything thoroughly before reconnecting the water lines.

It’s a straightforward process, but it requires the right tools and a careful touch. (I’ve seen plenty of DIY jobs gone wrong—trust me, you don’t want a garage full of vinegar water.)

Professional vs. DIY Flushing

Can you flush your tankless water heater yourself? Technically, yes. Should you? That depends.

If you’re handy, have the equipment, and don’t mind the smell of vinegar while it circulates through the system, you can attempt it on your own. But for most homeowners, it’s faster, safer, and less stressful to call in a pro like Clog Heroes Plumbing, Sewer & Drain.

We not only flush the system but also check for leaks, test the components, and make sure everything is working the way it should. It’s like getting an oil change and a 30-point inspection all at once.

How Flushing Protects Your Investment

Tankless water heaters aren’t cheap, and with proper care, many can last 15 to 20 years. Regular flushing is what makes that possible. By clearing out mineral buildup, you reduce wear and tear, prevent clogs, and keep efficiency high.

The U.S. Geological Survey notes that hard water often leaves “a scaly deposit on the inside of pipes, boilers, and tanks” — the same kind of buildup that can shorten a tankless system’s life if it isn’t flushed.

Skipping routine maintenance doesn’t just reduce efficiency; it can shave years off your system and force costly replacements much sooner than expected.

Quick Lifestyle Tip

Want to make flushing less of a hassle? Mark it on your calendar for the same time each year. Tie it to another seasonal chore—like changing HVAC filters in the spring or winterizing outdoor faucets in the fall. That way, you won’t forget. (We all know how “I’ll do it later” usually goes.)

Final Answer: How Often Should I Have My Tankless Water Heater Flushed?

So, to wrap it up: how often should I have my tankless water heater flushed? Once a year for most homes, and twice a year if you’ve got hard water or notice performance issues.

At Clog Heroes Plumbing, Sewer & Drain, we’re here to keep your hot water flowing and your system running at its best. Don’t wait until your tankless water heater throws in the towel—schedule your flush today and save yourself the stress of unexpected cold showers.

If you’re in Fredericksburg, VA or nearby areas, our licensed plumbers are just a call away.

Contact Clog Heroes Plumbing, Sewer & Drain

Need reliable plumbing help? Whether it’s tankless water heater maintenance, sewer repair, or drain cleaning, our team is ready. Call us today at (540) 518-4564 (CLOG) or use our online form to book service. We proudly serve Fredericksburg and the surrounding communities.

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