Potterton LPG 50e Installation And Servicing Manual page 23

SERVICING INSTRUCTIONS - Page 23
C. Refit the screw securing the gas control valve to the support
bracket.
D. Reconnect electrode lead to electrode.
E. Plug gas control valve supply leads into control box.
F. Reconnect gas supply at gas service cock and turn on gas.
G. Refit the combustion chamber front panel.
6. FAN
A. Carefully clean any deposits from around the fan motor and its
supports.
B. Very gently clean the fan impellor taking care not to damage
the aluminium impellor or dislodge its balance weights.
C. Replace the fan and its mounting plate. Ensure that the
securing screws are fully tightened as an air tight seal must be
obtained between the fan assembly and the main boiler
casing.
D. Reconnect the fan supply leads (polarity is not important).
7. CASE SEAL
Check the case door seal. Replace if damaged. The seal is
simply pressed into the channel around the door.
8. RECOMMISSION
Follow the full commissioning procedure as detailed in the
COMMISSIONING section of these instructions page 18.
9. OTHER BOILER MOUNTED UNITS
No further servicing is required on any other boiler mounted
units. Repair is by replacement.
10. FAULT FINDING
Refer to Fault Finding Chart FIG. 31 and Wiring Diagram
FIGS. 27, 28.
REMOVAL/REPLACEMENT OF BOILER MOUNTED UNITS
GAS CONTROL VALVE
This operation is most easily carried out by first removing the
burner and gas control valve assembly as follows:—
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, case door and combustion chamber
front panel as described in 1. 'Preparing the Boiler for
Servicing', operations A, B and C.
3. Remove the burner and gas control assembly as described in
1. 'Preparing the Boiler for Servicing', operations I, J, K, L and
M.
4. Disconnect the electrical supply wires from the gas control
valve noting their position. Refer to FIGS. 27, 28.
5. Unscrew the union connecting the pilot supply pipe to the gas
control valve.
6. Separate the gas control valve from the flanges at the inlet
and outlet ports by removing the securing screws.
NOTE: A spacer is used between the valve outlet and the burner
flange, requiring the use of two seals at this point. See FIG. 26.
7. Use new seals on reassembly.
8. Replacement is the reverse of removal.
9. Follow the full commissioning procedure as detailed in the
COMMISSIONING section of these instructions. Page 18.
FAN
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 and case door as described in 1.
'Preparing the Boiler for Servicing', operations A and B.
3. Disconnect the fan supply leads from the connnector adjacent
to the fan.
4. Remove the screws securing the fan to the mounting plate
and remove fan.
5. Replacement is the reverse of removal.
6. Follow the full commissioning procedure as detailed in the
COMMISSIONING section of these instructions. Page 18.
MAIN BURNER
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, case door and combustion chamber
front panel as described in 1 'Preparing the Boiler for
Servicing', operations A, B and C.
3. Remove the burner and gas control assembly as described in
1 .'Preparing the Boiler for Servicing', operations I, J, K, L and
M.
4. Unscrew the union nuts connecting the pilot supply pipe to the
pilot and gas control valve. Take care not to damage the
electrode.
Remove sealing grommet and withdraw the pilot tube through
the hole in the burner mounting flange.
5. Separate the burner from the gas control valve at the flanged
connection by removing the four securing screws.
NOTE: A spacer is used between the valve outlet and the
burner flange, requiring the use of two seals at this point. See
FIG. 26.
6. Unscrew the pilot, main burner injector and pressure test
nipple from the burner. On LPG 50e boiler access to the main
bumer injector is improved by first removing the air shroud.
See FIG. 29.
7. Use new sealing gaskets on reassembly.
8. Replacement is the reverse of removal. Ensure that the air
shroud is refitted on LPG 50e boilers
9. Follow the full commissioning procedure as detailed in the
COMMISSIONING section of these instructions. Page 18.
PILOT/IGNITION ELECTRODE
the external electricity supply by discon-
1. Switch off