Gas Inlet Pressure Monitoring Switch - Gdw1; Valve Seat Gas Pressure Monitoring Switch - Gdw2 - Viessmann Vitocrossal 200 CM2 400 Service Instructions Manual

Burner Service
Further Details Regarding the Individual Steps
Looking from underneath
Legend
A GDW1 - gas inlet pressure monitoring switch
B GDW2 - valve seat gas pressure monitoring switch
32
Front
Vitocrossal 200, CM2 400, 500, 620 and 620 TX Service
(continued)

Gas inlet pressure monitoring switch - GDW1

The factory default setting for the gas inlet pressure switch
is 10 mbar (4" w.c.). This is the minimum gas pressure
required for the burner to operate with natural gas fuel.
The inlet gas switch GDW1 will trigger a stand still (waiting)
state of the burner control unit when the gas pressure drops
below the setpoint. The burner will retry after 5 minutes if
the gas pressure returns to the setpoint threshold.

Valve seat gas pressure monitoring switch - GDW2

(outlet pressure at first valve seat)
The factory default setting for valve seat gas pressure switch
is 10 mbar (4" w.c.).
The switch will trigger an E1 (pressure) or E2 (open circuit
during control self diagnostics) faults on the burner control,
if activated.
IMPORTANT
Do not adjust this switch.