10 Best Submersible Pump For Flushing Tankless Hot Water Heater 2026 in the United States

The Wayne 58321-WYN3 CDU980E is a robust submersible sump pump designed for indoor use, particularly in basements. With a flow rate of 92 gallons per minute and a maximum lifting height of 32 feet, it offers substantial performance that could be beneficial for flushing tankless hot water heaters. The pump’s power source is corded electric, which ensures consistent performance without the need for battery replacements, but it does limit mobility to areas with power outlets nearby.

Build quality is a notable strength, with corrosion-resistant stainless steel and cast iron components ensuring longevity and durability in tough conditions. The ease of installation is highlighted, with users being able to set it up in about 15 minutes without the need for complex tools or drilling. The vertical float switch, tested for reliability, adds to the user-friendly design.

On the downside, the pump is relatively heavy at 12 pounds, which might make it cumbersome to move frequently. It’s also designed for indoor use, so outdoor or more portable applications might be less suitable. For those needing a durable, high-capacity submersible pump within a fixed indoor setting, the Wayne CDU980E is a strong candidate. However, if mobility and outdoor use are priorities, this might not be the best fit.

The WAYNE CDU790 submersible pump boasts a robust build with its cast iron and stainless steel construction, ensuring durability and longevity. This makes it well-suited for tough applications such as flushing a tankless hot water heater. It has a strong flow rate of up to 4,600 gallons per hour (63 gallons per minute), which should be more than sufficient for flushing tasks. The maximum lifting height of 10 feet is reasonable for most residential applications, though it may be slightly limiting if you have higher vertical requirements.

Being corded electric, it provides consistent and reliable power without the worry of battery life, making it ideal for regular maintenance tasks. The pump is designed for indoor use only, which could be a limitation if you need it for any outdoor maintenance. It’s relatively easy to use and install, taking about 15 minutes to set up, which is convenient for those who may not be very handy. The integrated vertical float switch and the top suction design help prevent air lock and clogging, adding to its ease of use and reliability. One notable advantage is the three-year warranty, reflecting confidence in its long-term performance.

The WAYNE CDU790 is a solid, dependable choice for flushing tankless hot water heaters, especially if you need a pump that promises durability and ease of installation. On the downside, it's a bit heavy at 16 pounds, which might make handling less convenient.

The Chromex Tankless Water Heater Flush Kit is designed for homeowners and professionals looking to maintain their tankless water heaters effectively. One of its key strengths is its compatibility with a wide range of brands, including popular names like Rinnai and Rheem. The kit includes a 1/6 HP pump, making it powerful enough for effective flushing, along with a citric acid-based descaling solution that safely removes scale deposits without being corrosive. This is a significant advantage, as it promotes the longevity and efficiency of the heater. The ease of use is also commendable, with 6-foot hoses that connect easily to heater valves and a quick cleaning time of about 30 minutes. Additionally, the included instructional infographic makes it accessible for DIY enthusiasts, even those with limited experience.

On the downside, the product's weight at over 14 pounds may be cumbersome for some users, especially when handling the entire kit. While it works efficiently, the necessity of using the kit periodically can be seen as a drawback for those who prefer a more maintenance-free solution. Furthermore, while the solution is safe for various materials, users need to ensure that their specific heater setup aligns with the kit’s compatibility. Lastly, the price point is competitive, but it may be considered a bit high for those only needing infrequent maintenance.

The Chromex Flush Kit is an effective and user-friendly option for flushing tankless water heaters, making it a good choice for those who want to extend the lifespan of their systems, despite some minor inconveniences.