22
Super Plus -
Installation and Servicing
3.
it the replacement screen ensuring:
(a) The slots in the screen are in line with the outermost points
of the finned tubes.
(b) The screen is held tightly against the finned tubes when the
securing screws are tightened.
4.
Re-assemble in reverse order to removal, renewing any
damaged or deteriorated gaskets as necessary.
Module Cover Filter
Pull the filter out from the bottom cover. Fit the new filter ensuring
that it is correctly positioned with the stiffening framework to the
bottom and central U cutout in the framework to the rear.
Wiring Centre (PCBs 10 & 15)
1.
Undo the 4 screws securing the wiring centre cover and remove
the cover.
2.
Disconnect the electrical leads from the printed circuit board
and earth posts - noting their positions - Refer to Fig.15.
3.
Undo the 4 screws securing the printed circuit board and remove
the Board.
4.
Fit the new board and reconnect the wiring (fig.15). Refit the
wiring centre cover and secure with the 4 screws and washers.
Fan
1.
Remove the fan and controls box assembly as previously
described under 'Burner'.
2.
Pull out the 2 push-on connections from the fan to the right
hand side of the controls box and undo the earth connection.
3.
Undo the 4 screws securing the fan housing to the controls box
assembly and remove it. Using an Allen key, undo the screw
securing the fan impeller to the fan and remove the impeller.
4.
To remove the fan motor, undo the 2 screws securing it to the
assembly.
5.
Fit the new part and reassemble in reverse order.
6.
Care must be taken when refitting the fan impeIler to ensure
that it does not foul the fan housing. If appropriate, unscrew the
pressure sensing probe fitting from the base of the old housing
and fit it to the new housing, If either sealing gasket is damaged
or deteriorated it should be replaceD.
Wiring Centre (PCB11)
1.
Undo the 4 screws securing the wiring centre cover and remove
the cover.
2.
Undo the 2 screws securing the filter to the top of the box (to
allow access to the PCB fixing screws).
3.
Disconnect the electrical leads from the PCB noting their
positions - refer to Fig. 14.
4.
Undo the 4 screws securing the PCB and remove the board.
5.
Fit the new board and reconnect the wiring (Fig 14). Refit the
filter with the 2 screws and shakeproof washers. Refit the wiring
centre cover and secure with the 4 screws and washers.
Spark Generator
1.
Pull the overheat thermostat coil, retaining strip and split pin
from the pocket in the flow elbow.
2.
Undo the 2 screws securing the 2 halves of the controls box
and carefully lower the front half.
3.
Pull out the spark electrode lead from the spark generator.
Unscrew the generator earth connection and the 2 electrical
connections at the terminal strip on the RH side of PCB No.12
4.
Undo the 2 screws securing the generator to the controls box
and remove it.
5.
Fit the generator and reassemble in reverse order.
Main Gas Valve / Main/Governor
1.
Undo the screws securing the electrical plugs to the main gas
valves and pull them out, complete with gaskets.
2.
Undo the iron union in the main gas train. Undo the 4 screws,
nuts and washers securing the main gas train flange and
remove the train complete.
3.
The gas valve(s) or governor can now be unscrewed and
replaced. Ensure the arrow on the replaced part points in the
direction of gas flow. Use approved jointing compound on all
gas joints.
4.
Check that, if the first main gas valve is to be replaced, the new
valve comes complete with the inlet strainer and a pressure
test point.
5.
Reassemble in reverse order.
Pressure Switch
1.
Pull off the 3 push-on connections on the side of the control
box and undo the earth connection.
2.
Unclip the pressure switch lead from the clip on the controls
chassis. Undo and remove the suction sensing line between
the pressure switch and the venturi casting. Undo and remove
the pressure sensing line between the pressure switch and the
fan housing.
3.
Unscrew the brass fixing nut holding the pressure switch to the
module bottom bracket and remove it.
4.
Fit the new pressure switch and reassemble in reverse order.
Ensure that the push-on connections on the pressure switch
lead are correctly made to the side of the controls box. In
particular NEVER connect the black wire to the blue connection.
5.
If the electrical wiring inside the pressure switch is disturbed it
is essential that it is reconnected correctly:
Blue wire to Common connection marked COM
Black wire to Normally Open connection marked NO
Brown wire to Normally Closed connection marked NC
Earth wire to Screw connection marked
Main Burner Injector
1.
The main burner injector is a screw fit into the end of the main
gas line. Unscrew the injector and discard it.
2.
Fit the new injector.
SER
VICING
SERVICING
