Carrier 30RB CHW Pump Failures

Lads,

Got a Carrier 30RB0262 with Hydroinic module. Only 3 years old and pumps are now tripping on their thermistors on start up giving a P32 and P33 alarm.

I have a pump discharge pressure of 2.2Bar, suction of 1.1Bar. Strainer has pd of 20kpa. Evaporator pd is 60kpa. Pumps are wound in star rated with a max current of 5.7A and we have around 5.2A on each.

Think there may be insufficient water in system but buffer tank on discharge of pumps so can't vent whilst pumps are running as always water present.

Any ideas?

check feed back wiring to controller, from pump contactors if
this tends to happen on these carrier modles
check your water flow sensor as well !