I am looking to replace a Watts hot water pump on our recirculating hot water line and would like some recommendations on a good replacement. We are not happy with the Watts pump for 2 reasons: (1) this is the second one that has broken down in 3 years, so their reliability seems poor (2) the Watts pump seems to cause hot water to back up into our cold water line (despite check valves and an expansion tank), and in looking into it more it seems to be more designed for a system that is not a closed loop. Our system is a complete loop all the way around the house and back to the pump so we would prefer a type designed for that type of system, as I'm thinking that is the reason the cavitation occurred with the last one.
I've tried looking online for replacements, but quickly got confused as there isn't a whole lot of description on the proper uses for each pump, just its hp rating and connections. We've got threaded pipe on the intake and outtake of our current pump. Anybody have a good recommendation for a replacement?