26
F1 2ATHRC
F2 1.25AT
Optional links
Spark
Flame sense
Outputs
Inputs
Mains
indicator
Modulating
valve
Overheat stat
X6
Pins 8 & 9
X6
Pins 15 & 16
X6
Pins 5,6 & 7
X6
Pins 1 & 2
X6
Pins 19 & 20
X6
Pins 3 & 4
Flow signal
CH temp. sensor
DHW temp. sensor
CH control POT
Air pressure switch
MAINS
PROGRAMMER/CLOCK
FULL SEQUENCE
CONTROLLER
GAS VALVE
LOW VOLTAGE
ELECTRONICS
(Microcontroller)
ROOM STAT
X1
X2
3 2 1
1
2
3
4
6
5
RL1
X3
Pin 1
X3
Pin 2
X4
Pin 3
X5
Pin 3
X5
Pin 2
X5
Pin 1
X4
Pin 1
FAN
PUMP
RL3
RL4
N
N
N
N
L
18. Fault Finding