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?