Baxi BOSTON 40 OF, Installation And Servicing Instructions, Page: 22 / 33

d) Remove the injector from the inlet manifold, clean carefully and replace.
14) Clean the pilot as follows: Unscrew the pilot tubing nuts at both ends and remove the pilot
tube. Remove and clean the pilot injector and clean the pilot shroud (
Fig 11 ).
15) Re­assemble the pilot components and then the burners in reverse order of dismantling.
16) Refit the burner and controls assembly checking that the door seal is undamaged. Replace if
necessary.
17) Reconnect the gas union at the service tap. Turn on the tap and check for gas soundness.
18) Refit the electrical socket and turn the thermostat to the OFF position.
19) Refit the outer case top panel.
20) Hold in the grey ON/OFF button on the gas control valve ( Fig 7 ). Press in the igniter button and
release. Repeat until the pilot lights. Hold in the grey ON/OFF button for a further 20 seconds and
then release. The pilot should then stay alight. (IF THE PILOT FAILS TO REMAIN ALIGHT, TURN
THE GREY ON/OFF BUTTON FULLY CLOCKWISE AND RELEASE, WAIT 3 MINUTES AND
START AGAIN FROM THE BEGINNING OF THE PARAGRAPH.) The flame should be without a
yellow tip and be approximately 25mm (1 in) long. No adjustment of the pilot flame is necessary as
with the restrictor screw fully open the pilot jet is sized to give the correct flame length at 20 mbar
(8 in wg) inlet pressure.
21) Turn on the electricity supply to the boiler.
22) Remove the pressure test point screw ( Fig 7 ). Connect a pressure gauge and operate the
burner by turning the thermostat knob to its highest setting.
23) Check that the pressure corresponding to the range rated output is correct for the installation
(see data label). If necessary remove the cover screw and adjust the appliance governor (
Fig 7 ).
24) Turn the boiler thermostat to the OFF position and refit the pressure test point screw.
25) Turn the boiler thermostat to its original setting.
26) Replace the outer case front panel.
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