27
7.10 FAULT CODES
When the boiler detects a temporary fault condition, the appropriate code is shown fl ashing on the display. If/when
the fault code is fi nal, the pump will perform a 60-second post circulation and the red LED will be illuminated.
COMPONENT
VALUE
Fan
230Vac
Pump
230Vac
Ignition transformer
230Vac
Gas valve
230Vac
Room thermostat connection
230Vac
NTC thermistor (dry contact)
10Kohm
NTC thermistor (wet contact)
10Kohm
FUNCTION
VALUE
Standard Heating Range (°C)
40 – 76
CH limited power at 75%
15 Min
Heating OFF hysterisis (
0
C)
SP + 2
Heating ON hysterisis (
0
C)
SP – 8
Anti-cycle delay
5-min
Pump over-run
5-min
Low output (min. %)
Min+25
CO function max temp. (
0
C) 87
CO re-light temp. (
0
C)
75
CO function time
15-min
Flow NTC max temp. (
0
C) 87
High limit thermostat (
0
C) 97
Burner thermostat (
0
C) 170
Maximum differential (
0
C) 35
IGNITION CONTROL
VALUE
Ignition attempts before L/O (lockout)
5
Re-ignition attempts after loss of fl ame signal 5
7.9 COMPONENT VALUES & CHARACTERISTICS
NOTE
Restore the electrical supply to the boiler and turn the
selector switch to the on position. The boiler should now
function as described in section 7.2. Should the boiler fail
to respond, the internal fuses and connectors should be
checked to ensure integrity and continuity. If the boiler
still fails to respond, refer to the detailed faultfi nding
fl owcharts located at the end of this section.
CODE
CAUSE
ALARM TYPE
ACTION
AL10
Ignition failure/not fl ame sensed, con-
dense sensor activated
Final
Reset, check appliance operation
AL20
Limit thermostat fault
Final
Reset, check appliance operation
AL21
External device fault (UHT/CPA)
Final
Reset, check appliance
AL26
Return temperature too high
Final
Reset, check pump, ensure there is suffi -
cient fl ow sensor temperature) circulation
around heating circuit/s
AL28
Temperature differential inverted (re-
turn sensor temperature higher than
fl owsensor temperature)
Final
Reset, check pump, ensure there is suf-
fi cient circulation around heating circuit/s
thermistors
AL34
Fan tacho signal fault
Final
Reset check appliance operation, check fan
AL52
Internal fault
Final
Reset, check appliance operation
AL55
Jumper tag fault
Final
Check jumper tag confi guration
AL60
Jumper tag fault
Temporary
Check jumper tag confi guration
AL71
Primary (fl ow) thermistor fault
Temporary
Check primary thermistor, check wiring
AL73
Return thermistor fault
Temporary
Check return thermistor, check /wiring
AL74
No water circulation
Final
Reset, check appliance operation, check
pump, ensure there is water and suffi cient
circulation around heating circuit/s
AL79
Flow temperature too high, or tempe-
rature differential between primary and
return too high
Final
Reset, check appliance operation, check
thermistors