Worcester 25/32 - Fault Finding Logic for 535 Se;Ld Rdb Control Box

FAULT FINDING
& DIAGRAMS
FAULT FINDING
I
NSTALLATION & SERVICING INSTRUCTIONS FOR WORCESTER GREENSTAR CAMRAY KITCHEN 12/18-18/25-25/32
8 716 113 000a (01/07)
49
Boiler not
operating
with a
heating /
hot water
demand
Burner
motor runs?
Lockout
within 1
second?
Replace
control box
Replace
motor/pump
Check boiler
controls &
supply
Replace
motor
Check L & N
to control
box
Motor or
pump
seized?
Photo cell
functional?
Solenoid coil
functional
(100Ω)?
Replace
photo cell
Motor gives
50 Volts on
white wire?
Lockout
after 12 sec
purge?
Replace
control box
Replace
solenoid coil
Replace
motor
Ignition
spark
proved?
Oil to pump?
Drive
coupling
broken?
Purge
pressure
1-2 bar?
Pump
produces
pressure?
Replace
pump stem
valve,
pressure
OK?
Replace
solenoid coil
Check pipe
to nozzle
holder
Replace
nozzle
Replace oil
pump
Replace
control box
Check the
electrodes
& leads
Yes
No
No
Yes
No
Yes
No
Yes
Yes
No No
Yes
Yes
No
No
Yes
Yes
No
Yes
Motor 40Ω
between blue &
black wires ?
Replace
control box
Yes
Yes
No
Yes
No
Yes
No
No
No
Yes
No
Nozzle
atomising
fuel?
Combustion
air setting
correct?
Yes
Yes
Combustion
head set
correctly?
Solenoid operating?
increase the pump
pressure
Solenoid coil
functional
(100Ω)?
No
Check coil
lead
Yes
Yes
Replace
control box
No
If BF
remove
burner
snorkle tube
& retest
Flame off &
re-lights?
Yes
Photo cell
functional?
No
Yes
Replace
photo cell
No
Boiler or flue
blocked
No
Reseal BF
or reposition
terminal
Yes
Replace
control box
Yes
F
AULT FINDING LOGIC FOR
535 SE/LD RDB CONTROL BOX
All resistance measurements are actual measured values and some variation is to be expected, therefore measured values should be similar to but not necessarily identical to the given values. The operation of the photo cell can be tested by measuring the resistance across the photo cell, it should be a high
resistance (greater than 10M
Ω or open circuit) in the dark and low resistance (3kΩ or less) in light.
Burners on balanced flue systems can recirculate flue products resulting in the burner cycling, if this happens check the
flue system integrity and the terminal position.