Review on Highly Efficient 110V NPT3/4'' Domestic Water Circulation Pump With 3-Speeds For Hot Water Recirculation And Solar Heater/Faucet Applications (RS15/6G) by Aaron Allen

My DIY project was to add a hot water recirculation loop to provide hot water to the kitchen sink and upstairs shower. The original 40 year old copper pipes are very long taking forever for hot water to arrive and and uninsulated that would cool off quickly after water flow stopped. I installed a new insulated 75' long 3/4" PEX loop to bypass the existing lines that used the BOKYWOX 110V 93W NPT3/4' 3-Speed Food Grade Pump to return hot water to the water heater cold water supply inlet. The pump is activated by a 12VDC N.O. IR motion sensor at both locations which trips a momentary input to the UCTRONICS DC 12V Programmable Multifunction Time Delay Relay. The timer is programmed to run the pump for 3 minutes, off for 5 minutes, and repeats if motion sensor trips again. At the highest flow rate it takes about 60 seconds for hot water to arrive from a cold start. The pump appears well built, quiet with no leaks. After about 2 months the pump is providing excellent service and would buy again.2 check valves are required, one to prevent hot water from entering the cold water loop and the 2nd one on the pump discharge to prevent backflow when pump is idle. Be sure to purge air from the return loop on initial startup, as this loop is vapor locked and pump is dry.