Baxi BOSTON 40 OF, Installation And Servicing Instructions

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2) Remove the outer case top panel by pulling upwards.
3) Remove the two facia retaining screws ( Fig 8 ) taking care not to lose the two spacer washers
and allow the facia to swing forwards on its hinges.
4) Release the thermostat capillary from behind its retaining clip and remove the thermostat phial
from the boiler (
Fig 8 ).
5) Remove the screw securing the thermostat cover to the facia.
6) Disconnect the three spade electrical terminals from the thermostat.
7) Pull off the thermostat knob and remove the locknut securing the thermostat to the facia panel.
8) Re­assemble in reverse order of dismantling ensuring that the thermostat phial is replaced into
the thermostat pocket.
HONEYWELL GAS VALVE (Fig 15)
1) Remove the burner and controls assembly as described in steps 1 to 6 ­ Servicing the Unit .
2) Disconnect the thermocouple nuts at the valve and at the pilot bracket.
3) Disconnect the pilot feed pipe at the valve and at the pilot bracket ensuring that the pilot injector
is not misplaced.
4) Disconnect the electrode lead and remove the piezo unit.
5) Remove the screw securing the electrical terminal cover to the gas valve. Disconnect the
electrical connections.
6) Remove the valve complete with the heat shield and inlet pipe by disconnecting the flanged
injector manifold.
7) Disconnect the flanged inlet pipe. Retain the O rings for re­assembly but replace if damaged.
8) Remove the heat shield by undoing the retaining screw.
9) Release the thermocouple re­route nut and remove the re­route.
10) lndividual sub components of the valve may be replaced as outlined by Honeywell instructions.
11) Re­assemble in reverse order of dismantling.
INSULATION IN COMBUSTION BOX
1) Remove the burner and controls assembly as described in steps 1 to 6 ­ Servicing the Unit .
2) Release the 2 screws securing the front insulation assembly and remove the assembly ( Fig 9 ).
3) Remove the two screws and washers securing the two side insulation panels ( Fig 16 ) and
carefully remove diagonally through the door opening.
4) Remove the two screws and washers securing the back panel insulation ( Fig 16 ).
5) Remove the ceramic insulation pad from the front insulation assembly by bending the securing
tabs.
6) 60,50,40 OF ONLY ­ Remove the two sloping panels of insulation adjacent to the heat
exchanger by removing 4 screws and washers. Ease out the bottom edge of the insulation panel