P a g e
| 47
LT7185 Issue No 1 (04/17)
780 HD SERVICE / FAULT FINDING INSTRUCTIONS
Shut off the restrictor elbow and disconnect the 8mm inlet nut.
Switch off the mains supply from the main supply plug socket.
Undo the two M3 nut retaining the ECU unit and remove the connection bracket plus
disconnect the mains supply cable from ECU.
Take out the three screw retaining the burner tray assembly and lift out of the fire box shelf
taking care not to damage the panels.
Remove the two side liner fixing bracket LH & RH which are situated in the roof of the fire box
assembly.
Carefully remove the LH & RH side panels.
Remove the rear panel from within the fire box.
Finally remove the eight screws from the inner and outer inspection covers. (Please see figure 1)
With the covers removed. The catchment area at the rear of the fire box can now be inspected
for debris. With the aid of a mirror via the back of the box check the path of the flue for any
restrictions. Re-assemble in reverse order.
Pilot Linting
Check the pilot aeration hole for linting, use a vacuum clearer nozzle taking care not to
damage the pilot head. Do not blow compressed into the pilot as this can lodge debris in the
pilot body.
Electrode Gap
The electrode gap should be 4mm from the tip of the thermocouple probe head to the end of
the electrode wire.
