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

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ANDREWS COMBIfl o 50 GB
5.6 FAULT FINDING
5.6.1 OPERATION SEQUENCE
To operate this appliance you must have a mains gas supply, 230v 50Hz electricity supply and a valid demand from
either the DHW or the space heating system.
1. The gas control starts the Ignition sequence following a demand for DHW or Space heating.
2. The Fan operates on the fi rst heat engine as a pre-purge of the heat exchanger airways.
3. After 30 seconds of fan operation, a spark is created at the electrode and the gas valve is opened immediately
afterwards.
4. The ignition spark will last for 5 seconds, followed by a stabilisation period of a further 5 seconds.
5. At the end of the stabilisation period the controls will check that a fl ame is present. If no fl ame is detected
stages 1 - 5 will be repeated up to 4 times before a permanent lockout of that heat engine occurs.
6. On successful confi rmation of a fl ame, the fan speed is then changed by the control to suit the demand
conditions.
7. After a short delay (normally within 2 minutes, but dependant on demand) the sequencing control will release
other heat engines, and these will follow stages 1 - 6.
NB If a heat engine is in a lockout condition , this should not aff ect the other heat engine/s ability to function
and the appliance should continue to operate as normal, using the other heat engine/s.
5.6.2 FAULTS AND LOCKOUTS
If any heat engine is unable to ignite or detects a safety condition, the control of that heat engine will lockout and
will be prevented from fi ring again, without manual intervention. The display will show the symbol along
the top bar of the GUI display to indicate that there is a fault, and the green LED on the appropriate LMS14 control
PCB will fl ash.
The fault will have to be cleared before that heat engine will function again. Selecting from info pages menu
will provide the fault detail (see section 6.6 at the end of this manual for the possible fault codes). Press the RE-
SET button and provided the condition has been corrected the heat engine will run through the ignition sequence
again.
CAUTION
A Lockout condition should not be repeatedly reset. If the condition persists then a qualifi ed repair
engineer should be called.
5.6.2.1 FAULT DISPLAY EXAMPLES
The display will show a if the appliance has recorded a fault. More information can be obtained by selecting
the info pages menu . See example screen:
Fault symbol
Info pages