
GB-13
D
GB
NL
RUS
PL
F
E
UA
CN
Press the RESET button to reset. The unit then
reverts to the last operating mode selected.
▷
Possible faults:
Display
Fault type
F
Flame fault
A
Air fault
C
Temperature fault
E
Electronics fault
U
Other possible faults
P
Gas-related faults
4
If the burner control unit does not respond even
though all the possible faults have been rectified
as described below, contact your supplier.
? Fault
! Cause
• Remedy
?
The 7-segment display has gone out despite
the voltage supply being OK?
!
Fuse F2 is defective.
•
Check the fuse contacts.
There is a spare fuse directly next to the fuse
holder.
Attention! Fit the correct fuse for 4 A.
L
N
L
N
N
LT
LV
+T
–
+V
mA
V
1
2
L
L
i
N
1
2
+
0 V
D – 49018 Osnabrück, Germany
ACU
?
Error code
P.
and
1
flash alternately and the
light is red?
!
Pressure switch does not switch.
•
Check inlet pressure p
u
.
!
Gas pressure on the burner too low.
•
Readjust gas pressure p
G
on the combination
control, see page 8 (Adjusting the heater).
!
Fuse F2 defective.
•
Replace fuse (3.15 A, slow-acting, H). Ensure
that only one heater is directly wired to the ther-
mostat, see page 3 (Wiring).
?
Error code
P.
and
2
flash alternately and the
light is red?
!
During three consecutive restarts, the gas pres-
sure switch has tripped during the safety time
or flame proving period (gas pressure switch
oscillates).
•
Inlet pressure fluctuates. Establish stable gas
supply.
•
Gas pressure p
G
too low. Readjust gas pres-
sure p
G
, see page 8 (Adjusting the heater).
? Error code
A.
and
1
flash alternately?
!
Vane switch switches off during burner operation.
•
Check the function of the vane switch, see
•
Vane, fan or grille are dirty. Clean, see page 18
•
Fuse F1 defective (8 A, slow-acting, H). Check
the function of the fan and replace fuse F1 if
necessary.
!
Motor defective.
•
Remove the device and return it to the supplier.
?
Error code
A.
and
2
flash alternately?
!
Vane switch does not switch off during the “no
flow” state check on burner start-up.
•
Check that the vane switch is functional, see
?
Error code
A.
and
2
flash alternately and the
light is red?
!
The fault “Vane switch” could not be rectified.
The programmed number of start-up attempts
having failed, the ACU initiates a fault lock-out.
•
Reset using the RESET button on the ACU or
via the remote reset.
•
Check that the vane switch is functional, see