Fault Finding & Diagnosis; Fault Finding; Protection Function (External Pump) - Worcester GREENSTAR 30CDi Installation, Commissioning And Servicing Instructions

7 FAULT FINDING & DIAGNOSIS
7.1

FAULT FINDING

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 installation error).
Display
code Description
b1 Code plug not detected.
C6 Fan speed too low.
E2 CH flow NTC sensor defective.
E9 Safety temperature limiter in CH flow has tripped.
EA Flame not detected.
F0 Internal error.
F7 Flame detected even though appliance switched off. Check electrode assembly, dry pcb. Flue clear?
FA Flame detected after gas shut off.
Fd Reset button pressed by mistake
Table 20
More detailed fault finding procedures are described in the Service booklet for the Engineer number 6 720 612 361.
7.2

PROTECTION FUNCTION (EXTERNAL PUMP)

6 720 806 548 (2013/02)
Remedy
Insert code plug correctly, test and replace if necessary.
Check fan lead and connector, and fan; replace as necessary.
Check CH flow NTC sensor and connecting lead.
Check system pressure, check safety temp. limiters, check pump operation,
check fuse on pcb, bleed appliance.
Is gas cock turned on? Check gas supply pressure, power supply, igniter
electrode and lead, ionisation sensing electrode and lead, flue duct and CO2
level.
Check electrical connector contacts, programmer inter-face module ignition
leads are not loose; replace pcb if necessary.
Check gas valve and wiring to gas valve. Clean condensation trap and check
electrode assembly. Flue clear?
Press reset button again
Pump anti-seize
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
Pump runs for 5 seconds
every 24 hours
FAULT FINDING & DIAGNOSIS
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