Technical data

21
To replace flame sense electrode
• Remove combustion chamber from boiler as
described in 'Routine Cleaning and Inspection'.
• Pull off lead from flame sense electrode.
• Unscrew and remove screw holding earth lead
to flame sense electrode.
• Unscrew and remove screw holding flame sense
electrode onto burner.
• Fit replacement flame sense electrode in reverse
order to removal.
• Refit lead.
To replace burner
• Pull off ignition and flame sense leads from elec-
trodes.
• Remove burner from boiler as described in 'Rou-
tine Cleaning and Inspection'.
• Remove ignition and flame sense electrodes as
described in previous sections.
• Unscrew and remove two screws holding burner
injector bar to burner and remove injector bar.
• Asemble replacement burner, supplied in parts,
as follows:
• Fit burner injectors to injector bar and tighten.
• Assemble burner elements (14) into front and rear
burner supports with securing pins and rods, using
original burner for guidance.
• Fit burner injector bar to burner.
• Fit ignition and flame sense electrodes to burner.
• Fit replacement burner to boiler in reverse order
to removal.
SERVICING INSTRUCTIONS
• Reconnect ignition and flame sense leads to
electrodes. Reconnect earth lead to flame sense
electrode. The polarity of the ignition leads is not
important.
To replace burner injectors
• Remove burner as described previously.
• Remove ignition and flame sense electrodes as
described in previous sections.
• Unscrew and remove two screws holding burner
injector bar to burner and remove injector bar.
• Unscrew and remove burner injectors from burner
bar.
• Fit replacement injectors to injector bar and
tighten.
Note: make sure that injector size, marked on each
injector, is the same as that given in 'Technical Data'.
• Reassemble burner and replace into boiler in
reverse order to removal.
To replace timeclock
• Gain access to rear of lower control panel as
described in 'Routine Cleaning and Inspection'.
• Unscrew and remove two screws holding
timeclock to lower control panel.
• Remove PCB cover.
• Remove timeclock plug from connection CN7
on main PCB.
• Fit replacement timeclock in reverse order to re-
moval.