Potterton Promax System HE Installation And Servicing Instructions page 40

Mains LED Flashing
Is
control knob
on ?
YES
Is
wiring from control
PCB to interface PCB
OK (F) ?
YES
Does boiler
produce heat ?
YES
Replace interface PCB.
40
NO
Switch on
NO
Rectify wiring.
NO
Replace control PCB.
14.0 Fault Finding
br
r
Ignition
PCB
br
Detection Electrode
w
bk
Condensate
g/y
Trap
Earth
Electrode g/y
Spark
Electrode
Control
PCB
bk bk
b bk
Dry Fire
b
bk
b br
Flow Switch
b
r
r
Gas
Transformer
bk
br br
Valve
Thermistor
Casing
Stat
br
g/y
b
bk
bk
N L
Pump
Overheat
Stat
S/L N P/F
Mains Optional
Input Pump Feed
F
w g br o o o o o o o o
r
b
DC
Fan
User PCB