The tankless recirculating units are much bigger than the non-recirculating units. Maybe you have to change out the tankless unit also. Our recirculating pump at our last house was picky on how it all worked depending on the temp setting of the circulating pump. If you set it too high, the pump would never stop because it was trying to get to a temp that would never materialize from the heater. Too low, and it would not recirculate because it met the desired temp.
|