Fer Falcon 47-26701 Installation, Servicing And User Instructions Manual page 21

FALCON
INDUSTRIE
Note: If the power supply cable has to be replaced, use "0.75mm (24/0.20) heat resisting cable only to BS6500 with a
maximum external diameter of 8 mm.
Note - When connecting a room thermostat or external timer, do not link the power supply of these devices to the switching
contacts. The switch contacts must be voltage free. Any mains powered devices must utilise mains power solely to drive
the timer motor.
Applying mains voltage to the switch contacts will irreparably damage the circuit board.
Although this boiler can also be used without a room thermostat, you are recommended to install one for the following
reasons:
Greater comfort conditions due to more accurate control of room temperature.
Greater energy savings.
3.10 Differential air pressure switch (fig. 2 - part 43)
The differential air pressure switch is a safety device which allows the main burner to ignite only after having verified that
the fan is working correctly. If the difference in pressure between the flue gas discharge pipe and the air intake pipe is not
at least equal to the minimum pressure switch calibration value, the pressure switch contacts do not close and the gas valve
is thus prevented from opening.
In addition, the electrical circuit of the boiler is designed so that if for any reason the air pressure switch contacts remain
closed when the fan stops, the burner will not start up again.
3.11 Checks
Fill the central heating system as described previously (3.07) and check there are no leaks in the domestic hot water and
boiler water circuits. Check that there are no gas leaks on the boiler or the supply to the boiler. Also check that the electrical
connections are correct.
3.12 Installing a room thermostat (72) (fig. 39 page 40)
To connect the thermostat:
Open the electrical box on the base of the appliance and remove the "jumper cable" between terminals 3 and 4.
Connect the room thermostat (72) as shown in figure 39.
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