Why Do You Need to Flush a Tankless Water Heater?

You flush the toilet every day. But when was the last time you flushed your tankless water heater? If you have owned a tankless water heater for over a year and aren’t sure what we’re talking about, it is probably time to flush it. Read on to learn why this procedure could be the best thing you ever do for your tankless water heating system.

What Is a Tankless Water Heater?

Unlike traditional water heaters, residential tankless water heaters lack a storage tank for hot water. Instead of heating and storing a quantity of water in a tank, a tankless heater quickly heats water as it passes through a heating element. Though tankless water heaters are usually more expensive than traditional water heaters, they tend to pay for themselves over time because they waste less energy. And since they lack a water reservoir, they are less susceptible to leaks.

How Does a Tankless Water Heater Work?

Tankless water heaters are available in both gas and electric models. When the tap is turned on, a flow sensor activates the heating element, and the water passes through it, warming it to the set temperature. No water is stored; it goes directly to the tap or appliance. Though tankless water heater systems are more expensive than traditional tank-based systems, they are more energy-efficient, especially electric ones. However, gas systems can usually provide a higher flow rate. 

What Is the Most Common Issue With Tankless Water Heaters?

While tankless water heaters have many advantages over traditional water heaters, they are not foolproof. One issue, especially in hard water (water with high mineral content) areas, is sediment buildup. Since water is being flash heated within a pipe, all dissolved elements become buildup, or scale, within the pipe. The result, finally, is clogged and eroded pipes. This can mean slower water flow and, eventually, system failure. That’s why tankless water heater maintenance is essential for your system’s functioning, and one of the most common maintenance procedures is flushing.

What Is Tankless Water Heater Flushing and How Is It Done?


At least once a year, and more often if you live in a more challenging water area, you should flush your tankless water heater system. As you might expect, this involves flushing the system with a cleaning agent that scrubs out mineral buildup. Kits are commercially available for this process. You will first shut off the water supply to the water heater unit, then attach a pump to circulate the cleaning agent through the system. Then, you will add the cleaning agent and allow it to circulate through the system (the kit will tell you how long it needs to circulate). Finally, you will flush the remaining cleaner from the system and reconnect all the hoses. 

While the flushing process is certainly not out of reach for a DIY-oriented person, it requires familiarity with hand tools, attention to detail, and time—sometimes two hours or more. For these reasons, many people prefer to hire plumbing professionals to flush their tankless water heaters. After all, paying for regular tankless water heater maintenance is better than paying for tankless water heater repair, and a botched flushing operation could potentially damage your expensive water heating system and even make re-piping necessary.

If you live in Jacksonville, Florida, Superior Plumbing and Pipe Lining is your solution. Our expert plumbers, backed by loads of rave reviews, will travel to your home at your convenience, flush your system, and ensure that your tankless water heater performs at optimum levels for years to come. Contact us to schedule a flush today. 

If you're contemplating the investment in a tankless water heater system, we are well-equipped to assist you in that endeavor. A dedicated team member can walk you through our options, considering your budget and hot water needs, and help you identify a solution that works for you and your family. Then, we can professionally install it for you, so all you have to do is sit back and enjoy the results. Start a conversation with us today about a new tankless water heating system.