Fault finding logic for satronic control box – Bosch 25/32kW User Manual
Page 47
Boiler not
operating
with a
heating /
hot water
demand
Burner
motor runs?
Burner
lights
immediately
motor runs?
23
0V at
solenoid coil
in purge?
Replace
control b
o
x
Replace
pump
23
0V at
motor?
Motor or
pump
seized?
Replace
motor
capacitor
Motor 4
0
Ω
across
L&
N
?
L & N
to
control b
o
x?
Control b
o
x
loc
ks out?
Chec
k b
oiler
controls &
supply
Chec
k
connections/
replace leads
Replace
motor/
pump
Replace
motor
Replace
control b
o
x
L
o
ckout
within 1
second?
Replace oil
pump
Oil to
pump?
Drive
coupling
broken?
P
ump
produces
pressure?
Replace
transformer
Electrodes
& leads
OK
?
23
0V at
transformer?
Spark
produced?
L
o
ckout
after purge
before oil
solenoid
opens?
Replace
control b
o
x
Transformer
lead O
K
?
Photo cell
lead O
K
?
Disconnect photo cell,
reset loc
kout, burner
lights then loc
ks out?
Stray light
on photo
cell?
Combustion
head set
correctly?
Combustion
air setting
correct?
Flame off
and
re-lights?
Nozzle
atomising
fuel?
Replace
photo cell
Photo cell
functional?
If B
F
remove
burner
snorkle tube
& retest.
Lights O
K
?
Replace
photo cell
Replace coil
lead
23
0V at
solenoid
coil?
Coil lead
OK
?
Boiler or
flue bloc
ked
Reseal B
F
on
reposition
Replace
control b
o
x
Replace
control b
o
x
S
olenoid
operating?
2.2k
Ω
across
solenoid
coil?
Pipe to
nozzle
holder O
K
?
Oil c
h
ec
k
valve O
K
?
(if fitted)
Replace
nozzle
Replace
solenoid coil
Replace
pump
Replace oil
ch
ec
k valve
(if fitted)
Yes
Yes
Yes
No
No
Yes
Yes
No
No
No
No
No
Yes
Yes
No
No
Yes
No
No
Yes
No
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
No
No
No
Yes
Yes
Yes
Yes
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
No
No
No
No
Yes
Yes
Yes
Yes
Replace
lead
No
Reset air
setting
No
Reset
combustion
head
No
FAULT FINDING LOGIC FOR
SATRONIC CONTROL BOX
Note: T
his c
hart assumes all wiring within the control box base is correct
, if in doubt c
hec
k the wiring against the diagram on
the base of the control box before replacing any components
.
All resist
ance measurements are actual measured values and some variation is to be expected
, therefore measured values
should be similar to but not necess
arily identical to the given values
.
T
he operation of the photo cell can be tested by measuring the resist
ance across the photo cell
, it should be a high resist
ance
(greater than 1
0
M
Ω
or open circuit
) in the dark and low resist
ance (
1
5k
Ω
or less
) in light
.
Burners on balanced flue systems can recirculate flue products resulting in the burner cycling
, if this happens c
hec
k the flue
system integrity and the terminal position
.
These fault finding charts are provided to assist competent and suitably qualified engineers to
locate and rectify faults. Whilst every effort has been taken to ensure the information given is
correct and complete we cannot guarantee that every eventuality has been covered.
Worcester, Bosch Group cannot be held responsible for costs incurred by persons not deemed
to be competent.
Measure all 230V tests between
Neutral (
N
) and the pin
, wire or
terminal specified
.
FAULT FINDING
INSTALLATION & SERVICING INSTRUCTIONS FOR WORCESTER GREENSTAR HEATSLAVE EXTERNAL 12/18-18/25-25/32
8 716 106 252b (07/06
46
FA
U
LT
F
IN
D
IN
G
& D
IA
G
R
A
M
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