I Tested And Reviewed 10 Best Recirculating Pump For Tankless Water Heater (2023)

I recently came across the idea of hot water recirculating pumps while searching for a small on-demand hot water heater for my kitchen sink. Living in a large, multi-level home, I realized that I was constantly waiting for hot water to reach different taps throughout the house. After doing some research, I decided to purchase and install a hot water recirculating pump to solve this issue.

The installation process was fairly simple, and I chose to install the pump in the guest bathroom, which happened to be the farthest from the hot water heater. I set the timer on the pump to run during the times when my wife and I typically use hot water, from 4 am to 10 am and 4 pm to 10 pm.

The results were impressive. While the hot water wasn't instantly available at the kitchen or master bathroom, it only took around 5 seconds for it to reach a comfortable temperature. The guest bathroom, on the other hand, had instant hot water during the specified pump operation times. The only drawback I noticed was that the sink with the valve would have lukewarm water instead of instant cold water for a short period of time.

One of the major advantages of this pump is its minimal power consumption. When considering the cost of operation, it is important to note that the pump saves thousands of gallons of water, making it a cost-effective and environmentally friendly choice. Additionally, the energy consumed by the hot water heater was not significantly increased. The pump's operation caused the hot water heater to run for a longer period of time rather than starting more frequently. This is comparable to a car's efficiency when cruising at a constant speed on the highway.

By setting up the timer to coincide with our hot water usage patterns, the runtime of the hot water heater was extended, resulting in minimal wasted energy. The water savings and reduced impact on the environment outweighed any increase in fuel consumption. For those with a well and septic system, like myself, this pump can relieve around 15% of water consumption from the well, reducing stress on the septic system.

Lastly, I would like to mention that this pump comes with a thermostatically controlled valve, eliminating the need to purchase a separate one. However, if you have a branched hot water line off the main line in your home, a second valve can be added to ensure instant hot water from all taps.

The installation process may take a bit of time, but it is relatively simple. However, the product description can be overwhelming and intimidating for beginners. Once you open the package, though, everything becomes clearer and easier to install.

The installation itself is very straightforward and only requires a couple of wrenches. Once installed, you will have hot water at the end of the run without any hassle.

I personally found it easy to install beneath my tankless water heater. It operates quietly, with only a slight hum that confirms its functionality. As a result, I now have instant hot water in my guest bathroom, even though it is located on the other side of the house. Additionally, it does not restrict the normal use of hot water when it is unplugged, so I can be conservative with the timer. In the worst-case scenario, I may have to wait a few seconds for hot water.

After using this system, I can confidently say that I don't know how we managed without it for so many years. The hot water is available quickly on all faucets, and the cold water in the kitchen is not affected when the pump is running. We can easily control the pump with a device on our smartphones. If we turn it off, the cold water returns to its normal temperature.

I do hear a little click when the pump kicks on, but it is not a major issue. Overall, this system has greatly improved our hot water setup, providing instantaneous hot water when needed.

I recently installed this product and although I usually prefer to wait a few months before giving a full evaluation, I wanted to share my initial thoughts for those who may be considering purchasing it. Let me start by saying, get it!

Before discovering this product, I was exploring various options for getting hot water to my bathroom sink, which is located quite far from the water heater. I considered expensive options like the Laing and Watt's pumps, but the Laing was too costly and the Watt's system had installation challenges with my hybrid water heater. That's when I stumbled upon this product – it had a peculiar brand name, poor English, and was priced significantly lower than the alternatives. I initially had doubts about its quality, but with the Prime guarantee and free returns, I decided to give it a try.

To my surprise, the product arrived within two days and the quality seemed good right out of the box. The plastic shell, although non-removable, felt solid and sturdy. The included components and fittings were of similar quality to those found at reputable home improvement stores. The installation process took me around 45 minutes, mainly due to the tricky positioning under my sink and the awkward angles. However, this was not a fault of the product itself. Once installed, I plugged it in and it immediately began working. The pump cycled for about 30 seconds and then shut off. When I turned on the hot water, I was delighted to find instant warmth. The product performed flawlessly with no leaks or any other issues.

One notable feature of this pump is its quiet operation. It runs for a short period of time and you'll barely notice it.

Here are a few things to consider before purchasing:

1. The instructions could be improved, but if you're handy and have experience installing plumbing supply lines, you should be able to manage.

2. Everything you need for installation is included in the package. Use the stainless 3/8" to 1/2" reducers to connect your existing supply lines to the copper tees. There's no need to disconnect your supply lines from the faucet.

3. To switch between modes, press and hold the button until the color changes.

4. Like most non-loop systems, this pump utilizes the cold water line to return water to the hot water heater. As a result, your cold water may become warm. If this is a concern, this product may not be suitable for you.

5. If the pump hasn't run for a while, the water may initially be lukewarm, but it is still a vast improvement compared to freezing cold water.

6. I cannot comment on the impact on my electricity bill yet. I have noticed the water heater running more frequently, but I don't anticipate a significant impact. Additionally, the savings on the water bill should offset any minor increase in electricity usage.

I recently purchased this pump as a replacement for my Bestway/Coleman Lay-Z-Spa, and I must say, I am impressed with its performance. My previous pump had a damaged impeller and impeller shaft, and despite my attempts to fix it, it was beyond repair. Instead of buying a whole new spa, I decided to give this pump a try.

Installation was fairly simple. I kept the old pump in place and disconnected the power to it. I then installed this pump under the "egg" between the intake line and the old pump intake. I had to cut the existing line and use clamps to attach it to this new pump. The result? A quiet pump with a nice, constant flow. I was pleasantly surprised by how quiet it was, as I could hardly hear it running. The flow sensors in the original egg unit still detected water movement, allowing me to use the heater without any issues.

I must mention that there is very little information available online about these inflatable spas, but this pump seems to work great for its intended purpose. It saved me from having to spend over $350 on a new spa when everything else was in working condition.

In addition to using this pump for my spa, I also used it for a DIY project. I wanted to add a hot water recirculation loop to provide hot water to my kitchen sink and upstairs shower. The original copper pipes in my house were old and uninsulated, resulting in long wait times for hot water and quick cooling once the water flow stopped. To solve this problem, I installed a new insulated 75' long 3/4" PEX loop and used this pump to return hot water to the water heater's cold water supply inlet.

The pump worked perfectly in conjunction with a 12VDC N.O. IR motion sensor and a programmable multifunction time delay relay. The motion sensor activated the pump, and the timer was set to run the pump for 3 minutes, followed by a 5-minute off period. This cycle would repeat if the motion sensor was triggered again. With the highest flow rate, it took about 60 seconds for hot water to reach the desired outlets from a cold start.

I am impressed with the build quality of this pump. It is well-built, quiet, and there were no leaks. After using it for around 2 months, it continues to provide excellent service, and I would definitely buy it again if needed.

I would like to note that when using this pump for a recirculation loop, it is essential to install two check valves. One check valve should prevent hot water from entering the cold water loop, and the second one should be placed on the pump discharge to prevent backflow when the pump is idle. Additionally, it is important to purge air from the return loop during the initial startup, as the loop may be vapor locked and the pump could run dry.

I purchased the stainless version of the BokyWox pump (RS15-6SB) and I am extremely satisfied with its performance. Initially, I bought a non-stainless version from a different "brand" (KolerFlo), and although I encountered some issues, I believe they would apply to this BokyWox line as well. Therefore, I want to share my experience to help others make an informed decision.

Firstly, the non-stainless version of the pump is prone to rusting. So, I highly recommend opting for the stainless version to avoid any potential issues in the long run. Additionally, if you find that your pump is not pumping enough water, I suggest trying different versions or even exploring other "brands" within this pump category.

It is important to note that the pump does not come with true NPT-fit threads, so it is crucial to ensure that it includes pipe fitting adapters with o-rings to prevent leaks. I faced difficulties in finding proper fittings and had to use additional teflon tape to achieve a leak-free connection. However, the stainless version of the BokyWox pump provided an adapter in the kit, which made the installation process much simpler and hassle-free.

The instructions provided with the pump are not comprehensive, and I found them to be quite inadequate. It is advisable to read reviews and do your own research to ensure you have a clear understanding of the installation process. Although it is not a complicated task, the lack of proper instructions can make you question your own intelligence.

One drawback of the pump is the absence of an "on/off" switch. To overcome this, you will need to use a switched outlet or a smart outlet for controlling the pump. Keep this in mind while planning your setup.

In terms of performance, the BokyWox pump has exceeded my expectations. It operates quietly and does not overheat or make any strange noises. After installing the pump, I was able to achieve a flow rate of approximately 0.5-0.6gpm through my water heater, which is sufficient for my needs. The pump has been functioning flawlessly for a couple of weeks now, providing a reliable water circulation system for my tankless water heater.

To summarize, I highly recommend the stainless version of the BokyWox pump (RS15-6SB). It is a reliable and efficient option, especially when compared to the non-stainless version like the KolerFlo pump. Ensure that your pump includes the necessary pipe fitting adapters with o-rings to prevent leaks. Although the instructions provided are inadequate, with some research, the installation process can be easily understood. Remember to plan for the absence of an "on/off" switch and make appropriate arrangements for control. Overall, the BokyWox stainless pump is a great choice for those in need of a reliable water circulation system.

I recently purchased this pump for my water heater and I am extremely satisfied with the performance and value for money. It effectively circulates hot water throughout my house, ensuring that all faucets have hot water readily available. The installation process was easy and hassle-free.

Initially, there was a slight smell coming from the hot water when the pump was first installed. However, this odor dissipated within two days, and we believe it was caused by some residual oil in the pump that gradually dissipated over time. Since then, we have not experienced any issues with the hot water quality.

Compared to a previous pump I owned, which cost three times the price and lasted only a year or two, this pump has proven to be a wise choice. It has been running flawlessly for six months, primarily on the 90-watt setting, without any problems.

One of the significant improvements we have noticed since using this pump is the instant availability of warm water in our master bathroom and kitchen sink. Previously, it would take a long time for the water to heat up, but now it is immediate. Additionally, the pump does not have a built-in timer, but I have connected it to a WiFi outlet and can easily set up a timer using my phone. This convenience allows me to turn the pump on or off remotely, making it incredibly convenient when leaving or returning home.

In terms of performance, this pump operates quietly and provides ample power to circulate the hot water effectively. Some users have mentioned that the threaded connections are 3/4 straight thread, which differs from the typical tapered (NPT) copper threaded pieces. However, I found a solution by using dielectric fittings with 3/4 FIP to 3/4 sweat ends. This not only ensures a secure seal with the help of Teflon tape but also allows for easy removal of the pump without needing to cut any pipes.

I have integrated the pump into my smart home setup by connecting it to a smart plug controlled by my Google Home. I have created a custom routine that activates the pump with a simple voice command, making it incredibly convenient to run the hot water for a specified duration.

Although I initially used this pump as a temporary solution for my radiant floor heating setup, it has exceeded my expectations. After one winter of use, I inspected the pump for corrosion and was pleasantly surprised to find it clean and in excellent condition. Consequently, I have decided to add a second one of this style to ensure reliable heating for my house. These "cheap" pumps have earned my confidence, surpassing the performance of more expensive alternatives that I previously used.

One user purchased this pump to circulate water through their solar hot water collector and found that it worked perfectly. They noted that it runs quietly and is of very good quality. They have been using it for two seasons and are extremely pleased with their purchase.

Another user used this pump to circulate water in a closed loop heating system and found that it worked great as a propagation chamber heater. They were satisfied with its performance and reliability.

One user has been using this brand of pump for a long time and decided to buy two this time to ensure their recirculating system never has a down day. They mentioned that all pumps eventually wear out, but they like this brand.

One user mentioned that this pump was an exact fit replacement for their previous pump. They were able to quickly swap it out with just an end wrench and had their water heating again in a matter of minutes. They also appreciated the warranty that comes with this pump. They mentioned that their water temperatures in Hawaii can get very high, so they will have to see how this pump holds up.

We recently purchased a small pump unit to address the issue of waiting for warm water in our kitchen sink. After exploring various options, we decided on this pump due to its compact size and ability to warm water for other faucets in the house as well. Overall, the pump performs as expected and meets our needs.

One of the notable features of this pump is its quiet operation. Although we can hear it running under the cupboard, it is not bothersome or annoying. Setting it up was also a breeze, as we already had an outlet for a garbage disposal. Connecting the hoses was straightforward, and we opted to purchase new ones for convenience.

Upon turning on the unit, we could hear it humming and working. It ran for a longer period compared to running hot water directly from the tap, but this was not a major concern. The water was immediately ready for use when we turned on the tap, eliminating the frustrating wait for warm water. Additionally, we tested other sinks in the house, and they all had warm water as well.

Although the water does not come out piping hot after a cycle, we were aware of this limitation before making the purchase. Our water heater is set to a higher temperature than the shut-off setting on the pump. However, the water is still immediately usable, and if caught right after a cycle, it will be warmer. It's worth noting that without a dedicated hot water return line, some sacrifices are expected. The cold water is slightly warmer now, and it takes about two gallons of running water to return to normal cold temperature. However, this is not a significant inconvenience for us, as we primarily use the kitchen sink for warm water purposes.

The pump also features a timer setting, allowing us to specify the hours of the day it operates. We typically leave it in the full-on position to ensure continuous access to warm water. While other pump models from the manufacturer offer an adjustable on temperature, we are satisfied with this pump's performance and appreciate not having to spend extra money on additional features.

As an additional convenience, we added a smart plug to the outlet, allowing us more flexibility in scheduling between weekdays and weekends, as well as day and night. This has resulted in energy cost savings, as the pump does not run when we are sleeping or during weekdays when it is not needed. Furthermore, we can even control the pump using voice commands through Alexa, providing further convenience and energy efficiency.

The Rinnai RL94iN tankless water heater is a great replacement for the previous model, the R94LSi. One notable improvement is the enhanced scale detection feature, which helps control mineral scale deposits. In terms of installation, I found it to be straightforward and completed it over a 3-day weekend. I opted for a simple installation without additional recirculating systems or buffer tanks.

One concern I had before purchasing the RL94iN was the "cold water sandwich" effect, which some reviews mentioned. However, after using it for a month, I realized that this effect is only rarely experienced when I increase the temperature to 140°F. When the temperature is set at 120°F, we never encounter this issue. Additionally, the wait time for hot water is similar to what we used to experience with a tank-style heater, with only a few extra seconds added, which is hardly noticeable.

The most significant comfort change I noticed with the RL94iN is the consistent water temperature during showers. Unlike with a tank-style heater where I had to adjust the hot and cold water multiple times, with this tankless unit, once I set the shower handles, the water temperature remains perfect throughout the entire shower duration.

In terms of noise, when the unit kicks on, it produces a sound similar to a cat purring or an airplane quietly revving up its engine in the distance. This was not a major concern for me as I primarily chose a tankless water heater for its space-saving benefits. However, I have come to appreciate the endless supply of consistent water temperature as well. Initially skeptical about tankless units, I am now extremely satisfied with my decision to go tankless.

Regarding the maximum temperature, the RL94iN is advertised as going up to 120°F. However, there is a DIP switch setting underneath the cover that allows it to reach up to 140°F. It is important to note that the maximum temperature is limited to 120°F for safety reasons, but it can go even higher with a commercial temperature controller option. I also found that the unit remembers my temperature setting when the power goes out and is restored.

When it comes to the gas line, I handled most of the installation myself, but I did hire a plumber to run a second 1" gas line from the meter. It is crucial to ensure a good gas flow, so if your existing gas line main branch is not large enough, it is essential to branch a new T all the way from the meter. While some plumbers may tell you that your existing gas line is sufficient, it is advisable to double-check and perform the necessary calculations. In my case, I confirmed that my existing gas line could not handle the demand after researching gas line sizing tables online.

For installation, there is nothing overly complicated apart from basic plumbing and mounting. However, I recommend installing a service valve kit, such as the Rinnai (Webstone) WRIK-C, if you are comfortable with soldering copper. When using the Webstone valve, remember to remove the rubber gaskets before soldering, and make sure to apply plenty of Teflon tape or pipe dope on the gas relief valve and tighten it properly. These Webstone valves have a reputation for leaking at the gas relief valve if not tightly secured.

In terms of venting, the Ubbink vents work well with the RL94iN, serving both as combustion air intake and exhaust in one double-layer pipe. To determine the necessary parts to order based on your specific venting requirements, refer to the Ubbink install guide PDF available online. I found the vent installation to be simpler than expected, as the pieces can easily be pushed together to form a tight seal. When cutting the vents to size, it is recommended to cut the metal inner pipe about 3/4 inch longer than the plastic outer sleeve to ensure proper mating.

The RL94iN comes with an actual-size paper template in the box to assist with wall mounting. To provide additional support, I opened the wall and inserted 4x4s between the studs before using 8 stainless steel bolts to mount the unit securely.

The manual mentions that the indicator will display a message if there is scale buildup, indicating when maintenance is necessary. Additionally, if you experience frequent brief power outages, you can connect the water heater to a computer equipment UPS battery backup device to ensure a continuous supply of hot water, as the RL94iN uses electricity for ignition.

The Takagi water heater is an excellent choice for those looking for a high-quality, efficient water heating solution. It provides hot water quickly and effectively. However, it is important to note that the installation process may require some time and effort. If you plan on installing it yourself, be prepared for a two-day project and multiple trips to the hardware store. It is advisable to inform your family in advance and make arrangements for hot water during the installation period.

The Takagi water heaters are known for their durability and reliability. They are well-made and offer a straightforward installation process. However, there may be some unexpected challenges when it comes to site selection and aligning the water pipes, gas pipe, and electrical outlet. Unlike traditional tank water heaters, the connections for the Takagi water heater are located along the bottom face of the machine. This may require some adjustments in your plumbing setup.

It is worth mentioning that Takagi is now owned by AO Smith, and many accessories are sold under the AO Smith label. These accessories have identical part numbers to the Takagi counterparts. One essential accessory to purchase is the valve kit, which is necessary for proper installation.

The reviewer had the Takagi water heater sitting in their garage for eight months before installing it. They had previously used a 50-gallon tank water heater, which was only three years old. The decision to switch to a tankless water heater was motivated by the desire to free up space in the garage. As a plumber, the reviewer had reservations about tankless water heaters in the past but acknowledges that they have improved significantly over the years.

The installation process was slightly tedious for the reviewer, especially since they had to relocate the water heater. However, if you are not moving the location, the installation should be easier. It is important to note that you may need to upsize your gas piping as tankless water heaters typically require larger gas pipes to accommodate their higher BTU output. The reviewer decided to upsize their gas piping from 1/2" to 3/4" to ensure optimal performance.

Despite the labor involved, the installation process is relatively straightforward and similar to that of a tank water heater. The reviewer was initially skeptical about using PVC pipe for venting but was pleasantly surprised by the efficiency of the Takagi water heater. The unit appeared to be 100% efficient, with no heated air coming out of it. The reviewer was impressed by the unit's quiet operation and the lack of hot gas exhaust.

While the reviewer is satisfied with the performance of the Takagi water heater so far, they do mention missing their water circulation pump. With the tank water heater, they were able to enjoy instant hot water at the faucet. Unfortunately, the pump they currently have is not compatible with the tankless heater. They are uncertain about the available options for water circulation with the new heater. The reviewer does mention that running water for a couple of minutes before getting hot water seems wasteful, but acknowledges that water is cheaper than gas.