Potterton Promax 15 HE Installation And Servicing Instructions page 38

No Switched Live
Is
boiler supply
fuse OK ?
YES
Is there
230 V at mains
input terminal
block (A) ?
YES
Is
there 230 V at
control PCB transformer
mains connection
(B) ?
YES
Is there
24 Vac at control
PCB transformer 24V
connection
(C) ?
YES
Is
control PCB
fuse F2 OK ?
YES
Replace control PCB.
38
Supplied By www.heating spares.co Tel. 0161 620 6677
NO
Replace with 3A fuse.
NO
No mains supply to
boiler.
NO
Replace control PCB.
NO
Replace transformer.
Check for short circuits
NO
on control PCB and fan.
If OK replace fuse.
15.0 Fault Finding
br
r
Ignition
b
PCB
br
Detection Electrode
w
Gas
g/y
Valve
Condensate
g/y
Trap
g/y
Spark
Electrode
A
Control
B C
PCB
bk bk
b bk w g br
r
b
DC
Dry Fire Fan
bk
b br
Flow Switch
b
r
r
Transformer
bk
br br
Thermistor
Casing
Stat
bk
bk
Overheat Stat
S/L N P/F
Mains Optional
Input Pump Feed
v
w
On/Off
Switch