Technical data

11
Fig. 13. Functional flow diagram.
On/Off
switch
ST2
(LS)
ST2
(L
R)
ST2
(N
S)
ST1
centre
pin
ST15
right
pin
Pump
Fan
ST2 Pin N
Optional link
Room
thermostat
Transformer
Fuse F2
(1.25A Slow)
Fuse F1
(2A Slow)
N
N
ST2 Pin L
LIVE
IN
Electronics
Electronics
Inputs
Outputs
Spark Indicators
Settings
Regulator valve
Spark
electrodes
Error
indicator/reset
Red
Main valve Flow sensor CH sensor DHW sensor Air pressure switch Flame sense Overheat cut-off 24V programmer (if applicable)
Gas valve mode switch
CH Control knob
DHW control knob
Convert AC to low
voltage electronics
Electronics/
microprocessor
(Safety Low Voltage)
Flame detect
indicator
Red
ST2
centre pole
(Ls)
(for other features)
low
high
Electronics
ST1
right
pin
Reset button
white
red