Burner; Injectors; Gas Valve; Modulating Valve - Potterton Puma 100 Installation & Service Instructions Manual

Component Replacement - Page 32
6.7

Burner

(Fig. 25)
a. Remove the white front case, air box covers,
combustion chamber, front panel and burner assembly.
See 5.1, 5.3, 5.6 & 5.8 in 'Routine Maintenance'.
b. Remove the electrodes or pilot burner from the main
burner and re-assemble onto the new main burner. (On
electronic only, check electrode gap is 4mm ± 0.5
Fig. 24).
c. Re-assemble in reverse order.
6.8

Injectors

(Fig. 25)
a. Remove the white front case, air box covers,
combustion chamber front panel and burner assembly.
See 5.1, 5.3, 5.6 & 5.8 in 'Routine Maintenance'.
b. With the main burner removed, release the burner
manifold by removing the 4 screws to give access to the
injectors.
c. Replace the relevant injector/s ensuring that the brass
washer is fitted under each injector.
d. Re-assemble in reverse order.
6.9

Gas Valve

(Fig. 28)
a. Remove the white front case, base panel & white left
hand side panel.
See 5.1, 5.2 & 5.3 in 'Routine Maintenance'.
b. Isolate the gas supply at the gas cock (1/4 turn).
c. On either valve remove the electrical connectors from
the modulating valve, the plug from the first solenoid
valve (Electronic & Saver only) and gas valve
compensation tube. On the permanent pilot version
remove the connections on the interrupter, spark igniter
and thermocouple. Disconnect the pilot tube.
d. Undo the nut on the lower gas supply tube.
e. Support the gas valve assembly and undo the nut on the
burner supply pipe under the air box. Remove the gas
valve assembly from the appliance.
f. Remove the second solenoid valve (2 screws).
g. Remove the screw and disconnect the electrical
connector to the second solenoid valve and remove the
rubber gasket.
h. Before the new gas control valve is fitted, fit the rubber
gasket to the second solenoid valve and secure the
electrical connector to the second solenoid valve (1
screw), transfer the burner feed pipe and lower gas
supply tube to the new valve. Replace the 'O' rings if
necessary. On Permanent pilot versions refit the
interrupter and the valve knob extension.
i. Re-assemble in reverse order ensuring that the black
and red wires (low voltage) are connected to the
modulator valve (Fig. 28 or 29) Polarity is not important.
6.10

Modulating Valve

a. Remove the white front case.
See 5.1 in 'Routine Maintenance'.
b. Disconnect the electrical connections to the modulating
valve. (Red and Black).
c. Remove the clear plastic cover by cutting off the nylon
tie, twisting the cover anti-clockwise 90° and levering off
with a small screwdriver.
d. Using a 14mm spanner unscrew the complete inner
cartridge and remove with niting plate.
e. Lift off the solenoid coil and remove from metal bracket,
f. Replace in reverse order ensuring the notch in theniting
plate is located over the raised pip on the new solenoid
coil.
g. Reconnect the red and black wires to the terminations
on the modulation coil. Polarity is not important.
h. Reset the gas pressure - see 3.4 'Commissioning', Page
21.
i. Refit the clear plastic cover, snap into place and turn.
6.11 First Solenoid Valve Coil
(Fig. 29)
(Electronic versions only)
a. Remove the white front case.
See 5.1 in 'Routine Maintenance'.
b. Disconnect the electrical connecter to the first solenoid
valve.
c. Remove the first solenoid valve (2 screws).
d. Replace the solenoid valve in reverse order.
e. Re-commission the appliance as described in section 3.
6.12

Second Solenoid Valve

(All versions)
a. Remove the white front case.
See 5.1 in 'Routine Maintenance'.
b. Remove the second solenoid valve (2 screws).
c. Remove the screw and disconnect the electrical
connecter to the second solenoid valve.
d. Transfer the rubber gasket to the new solenoid valve.
e. Replace the solenoid valve in reverse order.
f. Re-commission the appliance as described in section 3.
6.13 Case Seals
a. Remove the white front case, base cover and air box
covers.
See 5.1, 5.2 & 5.3 in 'Routine Maintenance'.
b. Peel off the existing case seal(s).
c. Fit new seal(s) and re-assemble, in reverse order.