Fault Finding - Worcester 440CDi Instruction Manual

BOILER - FAULT CODES AND CONDITIONS
Display
Code:
Fault description:
A5
Tank NTC defect
A7
DHW NTC defect
A8
EMS coms error
b1
Code plug not detected
b2, b3, b4
b5, b6
Data error
b7 Burner control error
C6
Fan defect
D3 External Temp limiter
D5
Condensate overflow
D6 Internal heatbank overheated
EA
Burner control lockout
E2
Primary NTC defect
E9
OH stat tripped
F0
Internal error
F1 Rom check error
F7
Flame detected after
apliance shut off
FA
Flame detected after gas
shut off
Fd
Reset button pressed
CONDENSATE PUMP - OPERATING LAMPS AND FAULT CONDITIONS
Ready for operation
Fault
Pump running
Operating lamps
Green Red
Off Off
Flashing Flashing
On Flashing
On On
Off Flashing
52

FAULT FINDING

Check, repair/replace as necessary:
check tank NTC and leads
check hot water NTC and connecting lead
check electrical connections.
Insert code plug correctly.
software/pcb error.
software/pcb error.
check fan, lead and connector.
check external stat.
check condensate pump and leads.
check tank overheat thermostat
check gas supply and igniter electrode.
check CH NTC and lead.
check system pressure and pump.
check electrical connector contacts.
software/pcb error.
check electrode assembly, dry pcb.
check gas valve and leads.
press reset button again.
= Steady green light
= Red light
= Flashing green light
Cause
Mains plug not plugged in
Power failure
Dry-run
(poss. air in pump)
Pump blocked
Level exceeds alarm level
Pump blocked and
alarm level exceeded
FAULT FINDING
NOTE ; This fault finding information is for
guidance only. Worcester Bosch cannot be held
responsible for costs incurred by persons not
deemed to be competent.
The electronic control system for this boiler
incorporates a blue central indicator. This
normally confirms the permanent mains supply,
but, by flashing during a fault, provides a guide
to the cause as listed.
This fault finding system assumes that the
appliance has been operating normally until the
time of failure (i.e. not a first time installation
error).
Preliminary checks:
Preliminary electrical system checks are the
first electrical checks to be carried out during
a fault finding procedure.
On completion of the Service/Fault finding
task which has required the breaking and
remaking of electrical connections, check:
a) EARTH CONTINUITY
b) SHORT CIRCUIT CHECK
c) POLARITY
d) RESISTANCE TO EARTH.
Solution
Insert plug
Check mains and fuse
Pump restarts automatically
after one minute
Visual inspection of the pump inlet
in the tank and removal or
rinsing out of dirt/foreign bodies
Pressure hose / non-return valve
blocked (clean or remove kink
if applicable)
Visual inspection of the pump inlet
in the tank and removal or
rinsing out of dirt/foreign bodies
INSTALLATION & SERVICING INSTRUCTIONS
8 716 115 219b (09.2008)