O Potterson CF 20/35, Installation And Servicing Instrucnions

Page: 37 / 43

This operation is most easily carried out by first removing the burner and gas
control valve assembly as follows:-
a)
Switch off the external electricity supply by disconnecting the plug at the sock
et or switching off external isolating switch.
b)
Remove boiler case and combustion chamber front panel as described in
1 P
REPARING THE BOILER FOR SERVICING operations A and B.
c)
Turn off the gas service cock and remove main burner assembly as described
in
2. MAIN BURNER ASSEMBLY -
REMOVAL AND CLEANING , operations A, B, C, D.
d) Disconnect the pilot supply tube at the gas valve.
e) Disconnect the thermocouple from the interrupter at the rear of the gas cont
rol valve.
f) Slide the blue wire with its plastic insulating boot from the thermocouple con
nection point at the rear of the gas control. Disconnect the black thermocouple
interrupter wirefrom the blue overheat thermostat wire at in-line connector.
g) Remove the four screws securing the burner manifold flange to the flange o
n the gas control valve outlet pipe.
Note: A spacer is used at this joint requirin
g the use of twosealing gaskets.
h) Remove the four screws securing the inlet pipe to the gas control valve. Re
placement is the reverse of removal. Use new sealing gaskets on reassembly.
Do notovertighten the rear thermocouple connection.
i)
Follow the full commissioning procedure as detailed in the
COMMISSIONING
section of these instructions.
Page 21
SERVICING INSTRUCTIONS - Page 22
PILOT ASSEMBLY and INJECTOR
Refer to section in SERVICING INSTRUCTIONS .
PILOT FILTER