andrews MAXXflo EVO Lite Assembling Instruction Manual page 17

Error Error Code
Code Description
110 SLT Lockout
111 Shutdown limit
thermostat
125 Maximum boiler
temperature
exceeded
126 DHW charging
temperature not
reached
127 DHW legionella
temperature not
reached
User operation
3.8.1 Error codes (continued)
Diag. Notes
Code
306 431 Electronic temperature limits exceeded. General overheating issue. Check for
432 433 pump operation, trapped air and heat exchanger blockages. Monitor tempera-
434 435 tures of system to establish problem area.
436 756
429 818 Safe reset of the error sub code 433 (see above) has not been met. Allow the
water heater to cool further before resetting.
305 412 Mechanical overheat protection circuit is open circuit (connection X18 on
550 551 control PCB). Check connector is fully inserted
754
426 437 Flow temperature heat up gradient exceeded. Check pump operation and
815 presence of trapped air in the heat exchanger. Flow through heat exchanger
may be restricted.
438 Maximum Delta T of system exceeded. Check pump operation and presence
817 of trapped air in the heat exchanger. Flow through heat exchanger may be
restricted.
428 Maximum Delta T of system exceeded. Initial starting of the pump before the
burner is operated, can cause this error. If accompanied by code 429 within
the same minute, this error can be disregarded.
429 Safe reset of the error sub code 428 /438 (see above). Allow the water heater
to cool further before resetting.
427 816 Safe reset criteria has not been met. Allow the water heater to cool further
before resetting.
420 421 Return temperature greater than fl ow temperature. Check that the fl ow and
819 820 return sensors are operating correctly
419 430 Flow temperature limit exceeded. Check for overheating issues and fl ow sen-
813 814 sor (B2) performance.
809 810 Flow temperature not plausible - Reading less than 0
422 423 124 O C . Check fl ow sensor (B2) and replace if necessary.
425 Return temperature limit exceeded. Check for overheating issues and return
812 sensor (B7) performance.
424 Return temperature not plausible - Reading less than 0
811 124 C . Check return sensor (B7) and replace if necessary.
O
264 Heat exchanger temperatures have been exceeded. Investigate fl ow rates
and controls to determine causes of temporary fault code.
286 500 Temperature supervision lockout. Check pump, shutoff valves, burner and
740 fl ow rates before resetting
501 Temperature has not increased at fl ow sensor after burner start. Check fl ow
sensor is correctly clipped to pipe work.
502 Temperature has not increased at return sensor after burner start. Check
return sensor is correctly clipped to pipe work.
72 Charging temperature not achieved within parameterised time scale. Check
operation and heat up times for heater
73 Check operation of legionella function and DHW system. Legionella setpoint
has not been achieved within 48 hours of the legionella function operating.
When using a secondary return system and sensor, do not set the legionella
function setpoint too high, as the heat losses of the hot water pipework may
not permit this setpoint to be achieved at the return point before the heater.
17
C or greater than
O
O C or greater than
MAXXfl o EVO Lite