Pump installation in dedicated recirc line to water heater
The pump you purchased is way oversized for the application.Instead of the "UP 15-29" pump you should have purchased a UP 10 or a UP 15-10, the smallest pumps they have. Make sure the pumps are made of bronze or stainless steel. Iron or steel pumps should not be used on domestic water.  The UP 15-29 moves too much water and may "wipe the elbows" (wear out or wear through) due to the high flow rate. You only need a very low flow rate to insure almost instant hot water flow at the faucets. I have 3 zones for the 3 bathrooms in my home. A check valve at the take off tee for each dedicated return line is imperative to stop "back flow" from the other dedicated returns. I would not use spring checks and use only angle checks due to required head needed to lift the spring checks. I would also install a timer to run the pump only during the day when your household is awake. No need to run the pump when everyone is asleep. continuous running pumps are only used in hospitals and large commercial buildings due to their constant hot water use.