Glow-worm Micron 40FF - Manual (Page 22)

22 221911E
Diagram 9.2
9 Fault Finding
10270
No
No
No
Before carrying out fault finding, ensure that gas, electricity and water are available to the boiler.
Ensure that any external controls are calling for heat and circuit water is cold.
If Reset LED is lit - check water system for overheating, reset by turning temperature control knob
off and on. If the LED coding is showing an ignition failure, reset the boiler by turning the control
knob off and on. Do not operate the boiler without combustion chamber front fitted.
Control Knob at '0'
Apply heating demand
(turn potentiometer clockwise)
Power ON at isolation switch
Does the fan run for 10 seconds with RESET LED lit Replace fuse
Does the unit begin to spark
Replace PCB Does the fan start Is there an LED sequence
Turn Gas ON
Is there an LED sequence
Is the Gas turned ON
Replace PCB
Replace PCB
Correct Operation
Does the burner light
Refer to table
Refer to table
Switch OFF
Remake connections
Restart diagnosis
Are the HT & Earth
connections made
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No No
Refer to table
Yes
Yes
Yes
Yes
No
No
No