andrews COMBIflo 100/300, Installation, Operation And Maintenance Manual

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ANDREWS COMBIfl o 71 GB
6.6 FAULT CODES LIST (CONTINUED)
Fault
Code
Fault Description Sub
Code
Notes
110 SLT Lock-out 306 431
432 433
434 435
436 756 Electronic temperature limits exceeded. General overheating issue.
Check for pump operation, trapped air and heat exchanger block-
ages. Monitor temperatures of system to establish problem area.
429 818 Criteria for the safe reset of the error sub code 433 (see above) has
not been met. Allow the boiler to cool further before pressing reset
again
305 412
550 551
754 Overheat protection circuit is open circuit (X18 STB). Check for
mechanical activation of the fl ow or rear heat exchanger temperature
limit switches. Investigate possible overheating issue, before replac-
ing any limit switches.
428 438
817 Maximum Delta T of system exceeded. Check pump operation and
presence of trapped air in the heat exchanger. Flow through heat
exchanger may be restricted.
426 437
815 Flow temperature heat up gradient exceeded. Check pump operation
and presence of trapped air in the heat exchanger. Flow through heat
exchanger may be restricted.
427 816 Criteria for the safe reset of the error sub code 426 (see above) has
not been met. Allow the boiler to cool further before pressing reset
again
420 421
819 820 Heat exchanger return temperature greater than fl ow temperature.
Check that the fl ow and return sensor is operating correctly
419 430
813 814 Flow temperature limit exceeded. Check for overheating issues and
fl ow sensor (B2) performance.
809 810
422 423 Flow temperature reading error. Temperature reading less than 0 O C
or greater than 124 O C . Check fl ow sensor (B2) and replace if neces-
sary.
425
812 Return temperature limit exceeded. Check for overheating issues and
return sensor (B7) performance.
424
811 Return temperature reading error. Temperature reading less than 0
O
C
or greater than 124
O
C . Check fl ow sensor (B7) and replace if neces-
sary.
111 Shutdown limit thermostat Any Heat exchanger temperatures have been exceeded. Investigate fl ow
speeds and controls to determine causes of temporary fault code.
125 Maximum boiler temperature
exceeded Any Flow temperatures have been exceeded. Heater will continue once
temperatures have dropped below maximum allowed limits.
126 DHW charging temperature not
reached Any Check operation and heat up times for DHW
127 DHW legionella temperature not
reached Any Check operation of legionella function and DHW system. Legionella
setpoint has not been achieved within 48 hours of the function operat-
ing. If using a secondary return sensor, do not set the legionella
setpoint too high, as the heat losses of the pipework may not permit
this to be achieved.
128 Loss of fl ame during operation Any Flame lost in heater operation more than 5 times in a 24 hour period.
Check the operation of the ionisation electrode, gas supply, and fl ue
system. View the ionisation current at high and low fl ame. Check CO
2
is correct
130 Flue gas temperature too high Any Check causes of high temperatures before operating boiler. Inspect
inside of heat exchanger for dirt build up. Check CO
2
levels at min
and max output.
133 Safety time exceeded Any Ignition unsuccessful after 5 attempts within a 24 hour period. Check
ignition and gas circuits for possible faults.