Boiler Function Module Hzs 521-G - Tetan KP 12S Service And Operation Manual

4.2.1 Boiler Function Module HZS 521-G

The heating system is modularly constructed. The HZS 521-G is a module for the boiler, which communicates
with the CPU module and executes the transmitted instructions. The HZS is a simple component that is used to
control automated processes in a heating system.
All interfaces and connections for controlling of the boiler are located on the control board.
Ambient temperature sensor
HC1 mix temp
Backwater temp
Sanitary water temp
Exhaust temp
Sanitary water top
Sanitary water bottom
Room thermostat 3
Room thermostat 2
SWT thermostat
Room thermostat 1
Impulse sensor 1
Impulse sensor 2
Room thermostat 4
Picture No. 3
The control unit always contains modules HZS 521-G a HZS 532-1.
Automatic boiler for wood pellets
HZS 521-G Connector and terminal electronics layout
11
Antifrost protection
Servo open
Servo close
SWT pump
Bypass pump
Ignition
HC1 pump
Primary fan
Exhaust fan
Feeder 1
Feeder 2