Quick Start Manual

12.0 Changing Components
34
12.8 Gas Valve (Fig. 52)
1. Undo the nut on the gas feed pipe under the boiler.
2. Remove the securing screws and hinge the facia panel
down.
3. Disconnect the earth wire and pressure sensing pipe
from the valve. Undo the screw securing the electrical
plug to the valve and disconnect the plug. Disconnect the
wires from the valve modulator.
4. Remove the screws securing the inlet pipe flange to
the boiler bottom panel and those securing the outlet
manifold to the burner manifold.
5. Remove the valve from the boiler.
6. Note the orientation of the inlet pipe and outlet
manifold. Undo the securing screws and remove the pipe
and manifold.
7. Examine the ‘O’ ring seals for damage, replacing as
necessary.
8. Fit the inlet pipe and outlet manifold to the new valve,
ensuring that the ‘O’ ring seals are in place.
9. Reassemble in reverse order and check the burner
pressure (Section 9.2).
12.9 Central Heating Temperature Sensor
(Fig. 53)
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 (Fig. 53)
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 (Fig. 53a)
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.
Gas Valve
Inlet Pipe
Gas Feed
Pipe
Earth Wire
Electrical Plug
Central Heating
Temperature Sensor
Safety Thermostat
Flow Pipe
Fig. 52
Fig. 53
DHW Temperature
Sensor
Fig. 53a
Plate Heat
Exchanger
Modulator
Wires