HAMWORTHY HEATING LTD
33
Wessex ModuMax
mk3
Boilers
500001308/C
Unplug the electrical connections to the transformer
noting the orientation and relative positions. Remove the
two pozi pan head screws securing the transformer to
the control panel and withdraw. Fit the new unit in
reverse order. Re
-
light the boiler and check for correct
operation.
11.9 Main Control
-
Navistem
Part Number
Model
533901756
-
WM97
533901758
-
WM116
533901760
-
WM147
533901762
-
WM196
533901764
-
WM254
Ensure that the boiler module electrical power supply is
isolated before removing the front cover and gaining
access to the controls. Also ensure that all other
supplies, particularly to the volt free contact outputs, are
also isolated.
If a ‘Clip in Module‘ is fitted, this must first be removed.
Carefully disconnect the plug securing the clip
-
in to the
Navistem Depress the locking latch at the connector
end of the clip in to allow the module to be hinged up
and disengaged from the Navistem.
Unplug the electrical connections to the PCB noting the
orientation and relative positions.
Fit the replacement PCB in reverse order as described
above. Remember to apply the parameters local to the
installation on initialisation
-
refer to the separate
Navistem manual. Re
-
light the boiler and check for
correct operation.
11.10 Clip in Modules
Part No. 533901776
-
Extension module
AGU2.550A109
Part No. 533901456
-
LPB module
OCI345.06/101
Ensure that the boiler module electrical power supply is
isolated before removing the front cover and gaining
access to the controls.
Carefully disconnect the plug securing the clip
-
in
module to the Navistem
Carefully disconnect the plug from the top of the clip
-
in
module.
Depress the locking latch at the connector end of the
clip in to allow the module to be hinged up and
disengaged from the Navistem or control panel.
Assemble in reverse order.
11.11 Display screen
Part Number 533901691
Ensure that the boiler module electrical power supply is
isolated before removing the front cover and gaining
access to the controls.
Carefully disconnect the ribbon cable connecting the
screen to the Navistem controller and the connectors to
the power switch. Remove the 4 screws securing the
screen panel to the controls pod. Unclip the screen from
the panel of the controls fascia and remove the display
pcb.
Remove the ribbon cable plug from the pcb and replace
the display in reverse order.
11.12 Low Gas Pressure Switch
Part No. 533901497
-
97/116/147
Part No. 533925004
-
196/254
Ensure that the boiler module electrical power supply is
isolated before removing the front cover and gaining
access to the controls.
Isolate the boiler module gas supply by closing the gas
service valve.
97/116/147
Disconnect the electrical plug after removing the
securing screw. Remove the switch securing screw and
withdraw the switch from the Brass adaptor. Fit the
replacement switch in reverse order using new ‘O’ rings.
196/254
Disconnect the electrical plug after removing the
securing screw. Remove the screw(s) securing the
switch to the gas valve body.
Fit the replacement switch in reverse order using new ‘O’
rings.
Set to correct pressure
-
refer to Appendix A.
11.13 Air Pressure Switch
Part Number 532496004
Ensure that the boiler module electrical power supply is
isolated before removing the front cover and gaining
access to the controls.
Disconnect the sensing tube from the switch (P1) noting
the position. Disconnect the electrical connections (1&2)
noting their position. Remove the 2 screws securing the
pressure switch body to the control bracket and remove
the switch.
Fit the replacement unit in reverse order.
P1
2
1
