1307SDH_RDH--EN,
page 18/32
Figure 11 : Pulley and drive belt adjustment
9.2 Ignition
system
o
Ensure that air discharge louvers are set to open.
o
Switch on electrical supply.
o
Turn on gas supply.
o
Set time switch (if fitted) to an 'ON' cycle.
o
Set room thermostat to 'ON' position.
o
If reset button on heater and/or on remote control (if
fitted) lights up, press reset button.
o
Thermostat calls for heat, energizing the venter
motor.
o
When adequate airflow for combustion is proven by
an air proving switch and a prepurge period has
elapsed, the integral igniter and multifunctional gas
control operate. The ignition spark ignites the gas
creating the burner flame.
o
Burner flame is sensed by a flame rod sensor and
when the heat exchanger is warmed up (+/- 30
seconds) and the fan control relay closes, the fan
motor is energized.
o
.If the flame is extinguished during the main burner
operation, the integrated control system closes the
main valve and attempts to relight the burner. The
unit will attempt 5 ignitions before entering a “lock
out” mode. Lock out is indicated by the red warning
light on the heater. To end this mode push on the
reset switch.
o
For a new installation or if the appliance has been
turned off for an extended period then up to 3
attempts to light the air heater may be necessary. If
the heater still does not light, consult the fault-
finding guide.
9.3 Operation
In case of a not continuous running fan (= ventilation),
simultaneously to the ignition circuit and gas valve circuit
being energised, electrical power is supplied to a time
delay relay that will activate the fan. The air circulation
fan will start after about 20 à 60 seconds.
In the event of the combustion air volume falling below a
safe level, the burner will be extinguished a re-start cycle
will commence after adequate combustion air volume has
been restored.
If the burner flame is extinguished for any reason during
a run cycle, an automatic attempt for re-ignition will take
place, if the burner does not relight after 5 attempts,
then safety shut down and lockout will occur. Manual
intervention to reset is necessary to put the air heater
back into service.
In the event of overheating for any reason, thermally
activated fail safe overheat controls operate to switch off
the burner.
The overheat control (LC3), will switch off the burner and
itself set to a lockout condition which also requires
manual intervention to reset to restore the heater to
operational condition. A cooling time of
1 minute is
necessary before thermal re-setting can be carried out
When the set temperature or the heating time period has
been reached, electrical power to the burner relay will be
switched off and the burner will extinguish. In case of a
not continuous running fan, the air fan will continue to
run for about 60 – 120 seconds until the heat exchanger
has been cooled down to a safe level.
To turn off the air heater for a short period
, turn room
a) thermostat to lowest setting.
b) to relight reset thermostat.
To turn off the air heater for prolonged period;
a) turn room thermostat to low setting or ‘OFF’ position
b ) shut off gas supply to the appliance
c) switch off electricity supply to the air heater after air
circulation fan has stopped.
d) to
relight
follow
lighting instructions.
The gas service tap must only be operated in
emergencies, for servicing or prolonged periods of
shutdown of the air heater.
