Potterton LPG 50e Installation And Servicing Manual page 24

SERVICING INSTRUCTIONS - Page 24
necting the plug at the socket or switching off the external
isolating switch.
2. Remove controls cover, case door and combustion chamber
front panel as described in 1 .'Preparing the Boiler for
Servicing', operations A, B and C.
3. Disconnect the electrode lead from electrode.
4. Unscrew the pilot tube from the pilot assembly. Take care not
to damage the electrode.
5. Unscrew the two hexagonal head screws securing the pilot to
the main burner and remove pilot assembly.
Remove the screw securing the electrode and withdraw
electrode.
6. Replacement is the reverse of removal. On reassembly
ensure that the spark gap is as illustrated in FIG. 30.
7. Follow the full commissioning procedure as detailed in the
COMMISSIONING section of these instruction. Page 18.
COMBUSTION CHAMBER INSULATION
1. Switch off the external electricity supply by disconnecting the
plug at the socket or switching off the external isolating switch.
2. Remove main burner as described in 'Preparing the Boiler for
Servicing', operations A, B, C, I, J, K, L, M.
3. Bend back retaining tabs and replace insulation. It is
necessary to first remove the side insulation when replacing
the rear.
4. Replacement is the reverse of removal.
5. Follow the full commissioning procedure as detailed in the
COMMISSIONING section of these instructions. Page 18.
FUSE, ELECTRONIC CONTROL, PRESSURE SWITCH, BOILER
THERMOSTAT, OVERHEAT THERMOSTAT, GRAVITY HOT
WATER/PUMP OVERRUN THERMOSTAT
The following initial operations 1-3 are necessary to remove and
replace any of the above items.
1. Switch off the external electricity supply by disconnecting the
plug at the socket or switching off the external isolating switch.
2. Remove controls cover by opening the door covering the
securing screw on the underside of the controls cover see
FIG. 14. Undo securing screw, pull controls cover forward
10mm, lower it to release it from its four side fixings and pull
forward clear of the thermostat knob.
3. Remove control box securing screw and lower control box.
FUSE 1 amp
4. The fuse is located on the electronic control and can be
replaced by lifting it from its holder.
5. Replacement is the reverse of removal. Refer to FIGS. 27, 28.
ELECTRONIC CONTROL
4. Disconnect six way plug, two way plug and electrode lead
from the electronic control. Refer to FIGS. 27, 28.
Disconnect the flying leads of the electronic control as
follows:—
white wire from terminal C(3) of the control thermostat
white wire from terminal NC(2) of the control thermostat
brown wire from overheat thermostat
blue wire from boiler terminal block connection N
green/yellow wire from earth post
5. Release the control by lifting it from the four retaining lugs.
6. Remove electronic control.
7. Replacement is the reverse of removal.
8. Follow the full commissioning procedure as detailed in the
COMMISSIONING section of these instructions. Page 18.
PRESSURE SWITCH
4. Remove the screw securing the pressure switch to the bracket
in the control box. Lift pressure switch from bracket.
5. Disconnect the two plastic tubes. NOTE: the red tube is
connected to the pressure switch connection identified with a
red ring or adjacent red spot.
6. Disconnect the three electrical leads, white wire from terminal
No. 1, or NC orange from terminal No. 2 or NO and brown
from terminal No. 3 or C. Refer to FIGS 27, 28.
7. Replacement is the reverse of removal. Ensure that the plastic
tubes are not kinked on re-assembly.
8. Follow the full commissioning procedure as detailed in the
COMMISSIONING section of these instructions. Page 18.
OVERHEAT THERMOSTAT
4. Remove door by undoing the two lower fixing screws and
lifting door off the two upper hinge brackets.
5. Disconnect the two push on electrical connections from the
overheat thermostat terminals.
6. Remove the nut securing the overheat thermostat to its
mounting bracket.
7. Noting the route taken by the capillary, loosen the plastic
screw retaining the thermostat bulb and withdraw bulb from its
pocket. Remove the split grommet in the base of the boiler,
feed the thermostat capillary and bulb through the hole.
8. Replacement is the reverse of removal. Ensure the rubber
grommet in the base of the boiler makes a good seal around
the capillary. Ensure that the capillary is secure in the clips
provided. Refer to FIG. 21.
9. Follow the full commissioning procedure as detailed in the
COMMISSIONING section of these instructions. Page 18.
BOILER THERMOSTAT
4. Remove door by undoing the two lower fixing screws and
lifting door off the two upper hinge brackets.
5. Disconnect the fan supply leads from the connector