25
221992D
9 Fault Finding
Diagram 9.4
BOILER PILOT FAULT FINDING
10176
MAINS SUPPLY
230V~50Hz
= MAINS ON
= DEMAND ON
= FAN RUNNING
= BURNER LIT
= SAFETY
TEMPERATURE
LIMITER
= FLAME FAILURE
NEON 1 =
NEON 2 =
NEON 3 =
NEON 4 =
NEON 5 =
NEON 6 =
NEON KEY (see P.C.B)
FAN
P.C.B (CONTROL BOARD)
GAS
CONTROL
VALVE
TERMINAL BLOCK
THERMISTOR
AIR
PRESSURE
SWITCH
NEON 1
NEON 5
NEON 4
NEON 6
NEON 2
NEON 3
F4A FUSE
p
y
g
p
b
bk
bk
bk
bk
b
bk
b
r
g
y
bk b
L
S
= LIVE (Switched)
N
L
S
N
br
r
g/y
g/y
g/y
g/y
br
b
b
br
BROWN
b
BLUE
g/y
GREEN/YELLOW
g
GREY
bk
BLACK
p
PURPLE
y
YELLOW
r
RED
KEY
g/y
= NEUTRAL
= EARTH MAIN
KEY TO TERMINAL BLOCK
br
