Potterton Performa 24i HE Installation And Service Instructions Manual page 33

12.0 CHANGING COMPONENTS
12.8 Gas Valve (Fig. 54)
1. Undo the nut on the gas feed pipe under the boiler.
2. Completely undo the securing screws and hinge
the facia panel down.
3. Disconnect the wires from the valve modulator and
the ignition lead from the spark generator. Disconnect
the pressure sensing pipe from the valve. Undo the
screw securing the spark generator electrical plug to
the valve and disconnect the plug.
4. Pull the earth wire off the spade terminal on the
valve.
5. Remove the screws securing the inlet pipe flange
to the boiler bottom panel and those securing the
outlet manifold to the burner manifold.
6. Remove the valve from the boiler.
7. Note the orientation of the inlet pipe and outlet
manifold. Undo the securing screws and remove the
pipe and manifold.
8. Examine the 'O' ring seals for damage, replacing
as necessary.
9. Fit the inlet pipe and outlet manifold to the new
valve, ensuring that the 'O' ring seals are in place.
10. Reassemble in reverse order and check the
burner pressure (Section 9.2).
12.9 Central Heating Temperature Sensor
(Fig. 55)
1. Ease the retaining tab on the sensor away and
disconnect the electrical plug.
2. Unscrew the sensor from it's pocket and
reassemble in reverse order. The electrical plug will
only fit one way.
12.10 Safety Thermostat
1. Pull the electrical connections off the thermostat.
2. Remove the screws securing the thermostat to the
mounting plate on the flow pipe.
3. Reassemble in reverse order. The thermostat is not
polarised - either wire can fit either terminal on the
thermostat.
12.11 DHW Temperature Sensor
1. Turn off the mains water supply and draw off the
residual domestic hot water.
2. Ease the retaining tab on the sensor away and
disconnect the electrical plug.
3. Unscrew the sensor from the plate heat exchanger
manifold. Examine the sealing washer,replacing if
necessary.
4. Reassemble in reverse order. The electrical plug
will only fit one way.
Publication No. 5111813
Ignition
Lead
Electrical
Flow Pipe
Central Heating
Temperature Sensor
(Fig. 55)
(Fig. 56)
Modulator
Wires
Plug
Earth Wire
Inlet Pipe
Gas Feed
Pipe
Fig. 54
Safety
Thermostat
Fig. 55
Fig. 56
Gas Valve
Plate Heat
Exchanger
DHW Temperature
Sensor
33