10
Fig. 9. Functional flow diagram.
F1 2ATHRC
F2 1.25AT
Optional links
SparkFlame 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
321
1
2
3
4
6
5
RL1
X3
Pin 1 X3 Pin 2
X4 Pin 3
X5 Pin 3
X5 Pin 2X5 Pin 1
X4 Pin 1
FAN
PUMP
RL3
RL4
N
N
N
N
L