Grundfos 98420224 UP 10-16 A PM BU/LC Comfort PM AutoAdapt Recirculation Pump

I replaced a 1/8hp Taco pump that was in my house and I suspect was original,(20 years old). The reason that I did this is I had developed a leak. As I did some internet research I learned that hot water circulation pumps are often over-sized leading to leaks. These pin hole leaks in copper pipes most commonly occur at elbows where there is turbulence. Your pipes are designed to tolerate appropriate flow for brief periods several times a day. They are not designed to handle excessive flow continuously. The taco pump had run continuously presumably for 20 years. I am glad that the leak occurred in the garage and not in the wall somewhere. I actually found adjacent brass check valves were leaking very slowly as well. I replaced all of these and it went as expected. The pump is silent and works fine. Grundfos makes good stuff. I was not sure what size pump to get. I am quite knowledgeable of pumps and fluid circuits but I had to make a reasonable guess as I do not know the details of my circuit through the walls. I looked over the pump curves etc. I considered getting a 1/40th hp or a 1/25th hp pump but settled on this one which is slightly less than 1/100th of a horsepower. I got impatient with the "auto" mode and the "temp time" mode so I am running it on continuous. The very slow flow provided should not erode the pipes even if run continuously and we use hot water off and on most hours of the day. big house 5BR with 4 adults. While the pump is running the outflow from the heater is 129 degrees F and the return at the pump is 108 as measured with infrared tele thermometer. By this difference it should in theory run continuously when on "time temp" mode. I did not find this to be true however. May evaluate further if I get bored enough but I am satisfied running it continuously as I do not see a meaningful advantage not to. It only pulls 6w per the brochure. If your pipes are poorly insulated you may have a greater temperature difference but that may be a virtually unsolvable problem. (For comparison the old pump went out at 129 degrees and came back at 129 degrees.... way too much flow.) My old pump also cost 50 cents a day just to run. In general I would discourage placing a pump larger than 1/25th horsepower. Even that is almost certainly too much. This pump changes modes at the push of a button. I have no complaints about this pump.

Needed to replace a 9 year old Grundfos due to the auto adapt function not working. Prices varied quite a bit between Amazon, Home Depot and various supply houses. That got me wondering if all were the same pump, so I started a text with Grundfos customer service. They were closed over the holidays, so it took me two weeks to finally connect with a rep. She was very helpful in telling me the 98420224 UP 10-16 A PM BU/LC pumps were all the same regardless who sold them. The replacement arrived within a week. I was very fortunate in that the plumber who plumbed my new home installed 1/2" shut off valves on each side of the pump, so isolating the valve was easy. I read the directions that came with the pump several times. The directions appear to have been updated in early 2024, so they were much improved over other reviews. With a large crescent and channel lock wrenches, the old pump came out easily. The new pump was exactly the same size so it went as easily. I was cautioned by the customer service rep to be very careful with the auto adapt cable and followed the directions verbatim. After flushing in both directions to ensure the pump had water, it plugs in and works well. An easy task.

This pump works great! At first I couldn't get it to actually move hot water even though the pump was running. The issue was that there was too much air in the line. The solution was open up each hot water source throughout the house until the air was out and then I had to bleed the air out at the pump itself. Since I did this, it's worked amazingly!

Overall easy install. The pump is ultra quiet, energy efficient but on the AUTO setting does not seem to really sync with day to day usage. We waited for the two week self-programming to complete, but its been well over a month now. We find that until you use the hot water in the mornings/mid-day the pump is not running. Once there is usage it seems to kick on to fill the lines and return with hot water. Considering setting to TEMP setting in lieu of AUTO. If I were to buy again more likely to get programmable version (for less money)

Love the adaptive recirculation. It recognizes our water use patterns and has the water hot at the faucet when we need it most. Saves about 5 gallons of water daily not having to wait for the water to get hot to our shower. Very small and takes up little space. Very quiet and uses less electricity than most pumps.

Easy to install and works very well very quite also.

our recirculator went out after 17 years in our house and - man you don't realize how nice it is to have instant hot water until - you don't have it and your house is a long ranch. My husband installed it and it worked right away. we tried the digital time electronics it has - but I guess I use water to randomly - I had to keep waiting for the hot water...so we just changed it to on all the time. it works great!

Purchased Grundfos 98420224 UP 10-16 A PM BU/LC Comfort PM AutoAdapt Recirculation Pump to replace old Grundfos pump. Install was easy and pump turns on but does not pump water. Seller/Amazon support is a loop of useless information. Would love to contact the seller for replacement and/or tech advise.