

🔥 Never wait for hot water again—comfort on demand!
The Grundfos UP15-18B5 is a premium 1/2" bronze circulator pump with a 1/25 HP motor and built-in motor protection, designed for continuous hot water recirculation. It saves over 11,000 gallons of water annually by maintaining instant hot water at taps, operates whisper-quietly, and supports multiple heating and cooling applications, making it a durable, efficient upgrade for modern homes.
| Brand | Grundfos |
| Color | Red |
| Material | Bronze |
| Power Source | Ac/dc |
| Product Dimensions | 12"L x 12"W x 12"H |
| Style | Circulator Pump |
R**T
Works great for recirculating hot water
Did the job paired with smart switch for ultimate control
D**E
Quality Made Grundfos
I recently replaced my 18-year-old water heater, along with the 18-year-old Grundfos circulation pump that was starting to make winding noises off and on. I replaced it with the "same" updated 2024-year Grundfos model. This pump is used to continually circulate hot water 24 hours a day in my house, which provides me with instant hot water everywhere I need it. Although the Grundfos brand is expensive, it is definitely worth the premium price as you get many years of trouble-free service. It runs smoothly just like smooth jazz music.
A**O
OEM Pump
These Grundfos pumps are a snap to install , and they work excellent
R**N
Grindr’s makes high quality pumps!
Using this on a dedicated return line for domestic hot water recirculation. I have used Grundfos pumps before and have had no issues. They seem to last forever. This is just a plain pump with no controls or timers. I used a countdown timer so as to not have it running too much. It gets the hot water there in 30 seconds. It saves so much water, as I used to run the faucet for about a minute or more to get the hot water. Good pump at a good price.
M**Y
Damaged
It was too damaged to install. Too bad; it was a good price. Bought a replacement for more through a plumber, but I didn't want to wait another 10 days for delivery after return.
M**M
Worked perfectly
Replacement for the original. Installed easily by a plumber. Worked perfectly.
J**K
i probably should have done more research on this but in the end it has worked out
I installed a recirculation system to prevent winter freeze ups vs. wanting instant hot water which will cost you plenty if you have thankless heaters because the burners will be running almost all the time. I have thankless hot water heaters: 2 in parallel installed in my attic. Even though I live in Texas and the units have “anti-freeze up” heaters they have frozen in the past and made a mess. So i decided to install hot water recirculation. Pump selection is important: as you may know thankless systems require a flow of .5 GPM or more before the burner fires. You need to check your units minimum flow requirement and measure your water pressure which translates into the minimum head pressure your pump needs to overcome to recirculate. Do not just rely on the pumps advertised GPM spec, flow will drop quickly as head pressure goes up. Check the pumps data sheet graph on flow vs pressure to be sure it can fire your thankless burner. I got this pump because it has high flow at high head pressure; 3-4x smaller lighter duty pumps. I installed it close to the units so I had a small loop to recirculate, allowing it to heat up fast and minimize wasted heat. No need for a timer as I only wanted it on when the temperature was freezing. Instead I got Grundfos Clip-On Aquastat Control (available in ½ and ¾ sizes so check you pipe). This easily wires into the pump and turns it on/off to keep the pipe at around 95 deg F. I plug the pump into an Easy Heat EH-38 (available on Amazon) which plugs into a standard outlet and only energizes when the temperature drops below 38 degrees. SO insummary: The set up works great, keeping the both the hot and cold water supply pipes around my units at a toasty 90 average degrees whenever the ambient temperature is below 38. Pros: * Good heavy duty solidly built pump * Excellent high flow at high head pressure * Very quiet operation. * Easy to wire * Great Grundfos accessories available (like the aquastat) * Many models to choose from – different power/flow/ pipe connection options. * Reasonable price Cons (** reason for 4 stars) * No built in check valve * Water will flow in either direction when pump is off This is where more research on my part would have paid off. When I first install this to recirculate it allowed hot water to flow back into cold, thus firing up the thankless burners whenever I turned on a cold water tap. It also let cold water mix directly with the hot when the pump is off. Time for some redesign. System 2.0 Added a ECHOTECK 120v Norm closed solenoid valve (also available on Amazon) at the pump and wired in parallel. Stops all flow unless pump is running. And I added inlet/ outlet valves to isolate the recirculation loop … just in case of a pump leak. The valve also allows for flow control so I can set the flow just high enough for the thankless burners to fire.
Z**U
Easy to install
My plumber found this easy to install and it runs fairly quietly. It was a replacement for one that died after many years and I am pleased with it.
Trustpilot
2 months ago
5 days ago