Grasslin Towerchron QM2 - Page 12

12
Always use special 24V thermostat supplied with this boiler, and wire as indicated in boiler instructions
substituting time switch terminals A and B for terminals 3 and 4 respectively on QM1�
Saunier Duval SD625M
Elm Leblanc GVM 420Boiler with timeswitch and room thermostat
N
D
COM�
S
room stat
D = demand
S = satisfy
COM = common
N
boiler terminals
L
50 Hz AC
220/240V
main supply
1L 2 3 4
240V 3 AMP
fused supply
240V
3 AMP
fused
supply
frost protection
thermostat (if required)
timeswitch
1
6
3
4
2
5
N
E
L
E NLBA
C
K
D H
J
thermostat
ground
boiler connection box