IX. Maintenance
Before and during the heating season, ST-550zPID controller should be checked for condition of its
cables. The user should also check if the controller is properly mounted and clean it if dusty or dirty. It
is advisable to measure earthing parameters for the motors (CH pump, DHW pump, fan, feeder and
circulating pump).
Maximum power consumption
Maximum output load of pumps: CH; DHW; Circulating; Valve
Output load of fuel feeder
Range of temperature measurement
Accuracy of temperature measurement
Range of temperature settings
Thermal resistance of the sensor