normally just stop the motormen from using washing powder to wash the deck, reroute the compressor and air bottle blow downs (the emulsification from them really screws up the readings) get new coalessor elements and everything should be dandy after that.
you have just confused the function of the pumps, the only duty of the circ pump is to circulate hot water around the circuit and heater, so that when someone in the accommodation turns a tap there is no delay in warm water flowing, so 8m3/h is plenty, when water is actually used the hydrophore...