System Components; Line-Voltage Motherboard; Low-Voltage Motherboard; Power Supply Unit Board - Viessmann VITOTRONIC 300 GW2 Installation And Service Instructions Manual

Additional information

System components

Line voltage motherboard, Part No. 7165 782
Low-voltage motherboard, Part No. 7820 290
Power supply unit board, Part No. 7823 991
Electronics board, Part No. 7828 193
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The motherboard contains:
Relays and outputs for activating
the pumps, the control elements
and the burner
Plug-in location for power supply
unit board and boiler control
section
The motherboard contains:
Plugs for sensors, communication
connections and external
equipment
Plug-in locations for electronics
board, LON communication module,
programming unit, boiler coding
card and Optolink board
The power supply unit board
contains the low-voltage supply
for the entire electronics.
The board contains the
microprocessor with the software
When replacing the board:
1. Make a note of codings and
settings on the control unit.
2. Replace the board.
3. Set coding "8A: 176" and set
coding address "92" (not listed
in the overview) to "92: 165".