Bosch 25/32kW - Manual (Page 45)

PROBLEM CAUSE REMEDY
LOCKOUT:
Pulsation on start Combustion settings incorrect Set up as in installation instructions
Faulty nozzle Replace nozzle
Intermittent lockout Bad electrical connection Check control box/electrical connections
Intermittent flame detection fault See flame detection fault
Burner motor fails to
operate Faulty motor or electrical supply
to motor Check for 230v at motor plug during
startup period
Control box fault Replace control box
Flame detection Photocell filmed over (dirty) Wipe clean
fault Photocell faulty Replace
Control box faulty Replace
Incorrect CO
2
Air adjustment fault Set up as in installation instructions
Oil pressure incorrect Set up as in installation instructions
No oil from nozzle No oil at pump Check and refill oil tank/bleed oil line
Check and clean filters & valves from oil
tank to boiler
Air in pump Bleed pump
Nozzle blocked Replace nozzle
Faulty pump or drive Replace
Faulty mechanical shut off valve Clean or replace
(12/18 & 18/25 only)
Ignition failure Electrode settings incorrect Set up as in installation instructions
Faulty ignition transformer Replace
Open circuit ignition Check and replace electrodes or high
tension leads if necessary
Faulty control box or electrical
connections not properly made Correct control box electrical
connections or replace control box
BURNER FAILS No power to boiler Check electrical / control circuit
TO START Faulty boiler thermostat Check by temporarily linking out high
limit and control thermostats
Programmer open circuit Check by temporarily linking 8 & 9 on
the connector
Faulty control box Replace
HIGH SMOKE Air intake/flue blocked Check & clear air intake/flue
NUMBER Incorrect combustion settings Set up as in installation instructions
Oil pressure incorrect Adjust to correct pressure
Incorrect components used on
combustion head Check with installation instructions
Faulty nozzle Replace nozzle
FAULT FINDING INSTALLATION & SERVICING INSTRUCTIONS FOR WORCESTER GREENSTAR HEATSLAVE EXTERNAL 12/18-18/25-25/32
8 716 106 252b (07/06
44
FA
U
LT
F
IN
D
IN
G
& D
IA
G
R
A
M
S
FAULT FINDING
BOILER LOCKOUT :
Indicated by the illumination of the 'Lockout'
indicator on the fascia.
To reset, wait 2 minutes then press the lockout
reset button.
Also refer to fault finding logic on pages
46 and 47.
UNDER NO CIRCUMSTANCES MUST AN
APPLIANCE BE LEFT TO OPERATE WITH
ANY CONTOL LINKED OUT OR
OVERRIDDEN.