10 Best Submersible Pump For Flushing Tankless Hot Water Heater 2025 in the United States

The 6699 Tankless Water Heater Flushing Kit is a comprehensive solution for maintaining your tankless hot water heater. It includes a 1/6HP submersible sump pump, two adapters, a 3-gallon pail with a bucket lid opener, and two 1/2” diameter x 6’ PVC hoses with washers. This kit simplifies the process of flushing your heater, ensuring it performs well and lasts longer.

The pump is energy-efficient, has thermal overload protection, and can reach a head height of 16.5 feet with a flow rate of 1100 gallons per hour, making it suitable for most domestic needs. Its 10-foot power cable adds convenience for easy use. The ergonomic bucket lid opener further eases handling, especially when dealing with tight lids.

On the downside, while the kit is quite complete, the vinegar or biodegradable cleaner needed for the flushing process is not included, so you’ll need to purchase that separately. Additionally, the maximum fluid temperature the pump can handle is 95℉, which should be adequate for most uses but is worth noting. The provided one-year limited warranty and responsive customer service are reassuring. This kit is a solid choice for homeowners looking to maintain their tankless hot water heaters efficiently and with minimal hassle.

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 DrainX Tankless Water Heater Descaling Flush Kit is designed to help keep your tankless water heater running smoothly by cleaning out mineral buildup. The kit includes a 1/6 horsepower heavy-duty pump, a 3.5-gallon bucket with a lid, and two 6-foot steel hoses that connect easily to most tankless water heaters. This setup is convenient because you just need to add vinegar or your preferred descaling solution (not included) to the bucket. The pump is powerful enough to circulate the cleaning liquid through your system efficiently, usually completing the flush in about 30 minutes or less.

In terms of durability, the steel hoses and sturdy pump suggest the kit is built to last through multiple uses, which is great if you plan regular maintenance. The pump size is typical for this type of maintenance task, balancing enough power without being overly complicated. Ease of use is a strong point here: the kit comes with clear instructions and a maintenance card, making it straightforward even if you’re not familiar with plumbing. It’s compatible with a wide range of tankless water heater brands, adding versatility. The pump is electric but doesn’t require batteries, so simply plug it in to operate.

One limitation is the lack of included descaling solution, so you'll need to buy vinegar or a cleaner separately. Also, the kit’s size and setup might feel a bit bulky for small spaces. For those seeking an effective and relatively simple way to extend the life of their tankless water heater through regular flushing, this kit offers a solid combination of power, durability, and ease of use.