Appendix; Fault Codes - Worcester benchmark ZWB 7-25 R 25 HE Design, Installation And Servicing Instructions

9

Appendix

9.1

Fault Codes

More detailed fault finding procedures are described in
the Service booklet for the Engineer number 7 181 465
346.
Display
code Description
Hot water NTC sensor defective.
A7
A8 Break in communication
AC Module not detected.
Code plug not detected.
b1
C1 Fan speed too low.
Jumper 8-9 not detected.
d3
E2 CH flow NTC sensor defective
Safety temp. limiter in CH flow has tripped.
E9
EA Flame not detected.
F0 Internal error.
F7 Flame detected even though appliance switched off.
FA Flame detected after gas shut off.
Fd Reset button pressed by mistake.
P1, P2, P3, Please wait, initialisation in progress.
P1...
Table 17
6 720 611 441 GB (03.11)
Remedy
Check hot water NTC sensor and connecting lead for
circuit breaks/short circuits.
Check connecting lead to programmer
Check connecting lead between TA211E/TR212E
and Heatronic
Insert code plug correctly, test and replace if neces-
sary.
Check fan lead and connector, and fan; replace as
necessary.
Connector not connected, link missing, underfloor
heating limiter tripped.
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
interface module ignition leads are not loose; replace
pcb if necessary.
Check electrode assembly, dry pcb. Flue clear?
Check gas valve and wiring to gas valve. Clean con-
densation trap and check electrode assembly. Flue
clear?
Press reset button again
24 V fuse blown. Replace fuse.
Appendix
43