On Wed, 13 Jun 2018 12:58:05 -0700 (PDT), wrote:

I have a Navian tankless water heater that I have had for about 8 years. I have had nothing but problems. I want to change it out to either a Rinnai or a Rheem water heater. I need about a 9.5 gpm or greater at 199,000BTU rating.
I already have the 3/4" gas line and the 3/4" water line and the condensate drain set up plus the 3" PVC vent lines so there is no reason to discuss these.
My question is which one is better. I would like one with a recirculating pump


I would suspect either one will be better than you had, as the
technology has matured somewhat - but either one is still liable to be
more trouble than "I" would put up with. Cut your losses and install a
tank unit.