To Remove The Electronic Ignition Generator; To Remove The Thermocouple Interrupter Block; To Remove The Pilot Unit - Baxi 748 Installer's Manual

16.7 To remove the electronic ignition generator.

1. Remove the burner unit (See section 16.6)
2. Remove the battery.
3. Remove the spark lead and microswitch leads
remembering to make note of their positions.
5. Unscrew the two fixing screws that attach the
generator unit to the support bracket. The igniter
generator can now be removed (See figure 43).
8. Replace the generator
9. Refit in the reverse order.
16.8 To remove the thermocouple interrupter
block.
(See figure 36).
1. Remove the burner unit (See section 16.6).
2. Detach the thermocouple from the interrupter
block by unscrewing the thermocouple nut.
3. Detach the two microswitch leads from the interrupter block.
4. Remove the interrupter block by unscrewing from the gas shut-off tap.
5. Refit in the reverse order. If the microswitch leads cannot be easily attached to the
interrupter block when it is fully tightened to the gas shut-off tap, slacken it and rotate
to allow the leads to be fitted. Retighten making sure that the leads remain in place in
the interrupter block. Fit and tighten the thermocouple nut making sure that the leads are
secured in the interrupter block to give a good electrical contact.

16.9 To remove the pilot unit.

1. Remove the burner unit (See section 16.6).
2. Detach the pilot pipe from the pilot unit.
3. Detach the thermocouple from the interrupter
block by unscrewing the thermocouple nut.
4. Detach the electrode lead from the underside of
the electrode tab.
6. Remove the two screws securing the pilot unit
(See figure 44).
7. Refit in the reverse order.
Note:
1. The pilot unit is an atmosphere sensing device.
It must be replaced as a whole assembly. Its
individual components are not separately replaceable.
2. When the thermocouple is removed from the interrupter block, the microswitch lead
terminals in the interrupter block will be loose. Make sure that they are properly
©
Baxi Heating U.K. Limited 2006.
INSTALLER GUIDE
Page 38
Figure 43. Removal of electronic
ignition generator
Figure 44. Pilot unit removal