6 720 610 576 GB (02.05)
Appendix
43
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
Remedy
A7
Hot water NTC sensor defective.
Check hot water NTC sensor and connecting lead for
circuit breaks/short circuits.
A8
Break in communication
Check connecting lead to programmer
AC
Module not detected.
Check connecting lead between TA211E/TR212E
and Heatronic
b1
Keyed plug not detected.
Insert keyed plug correctly, test and replace if neces-
sary.
C1
Fan speed too low.
Check fan lead and connector, and fan; replace as
necessary.
d3
Jumper 8-9 not detected.
Connector not connected, link missing, underfloor
heating limiter tripped.
E2
CH flow NTC sensor defective
Check CH flow NTC sensor and connecting lead.
E9
Safety temp. limiter in CH flow has tripped.
Check system pressure, check safety temp. limiters,
check pump operation, check fuse on pcb, bleed
appliance.
EA
Flame not detected.
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.
F0
Internal error.
Check electrical connector contacts, programmer
interface module ignition leads are not loose; replace
pcb if necessary.
F7
Flame detected even though appliance switched off.
Check electrode assembly, dry pcb. Flue clear?
FA
Flame detected after gas shut off.
Check gas valve and wiring to gas valve. Clean con-
densation trap and check electrode assembly. Flue
clear?
Fd
Reset button pressed by mistake.
Press reset button again
P1, P2, P3,
P1...
Please wait, initialisation in progress.
24 V fuse blown. Replace fuse.
Table 17