D) Description of Operation
Important: The heater must NOT be
controlled by switching ON and OFF the
main electrical supply to it.
1) Standard Units
The ignition sequence commences each time the external
controls e.g. Time clock, room thermostat etc. call for
heat. The internal exhaust fan will run and, when sucient
combustion airow is proved by the air pressure switch,
the ignition spark will be generated, the main gas valve
opens and the burners light. The green ‘ON’ indicator
will be illuminated. The heater fan will automatically start
approximately 2 minutes after the burners light. When the
external controls are satised the burners will be turned
o and approximately 2 - 3 minutes later the heater fan will
be automatically stopped. If the burners fail to light the
control box will make another four attempts at ignition.
2) High / Low & Modulating Units
When the burners are alight, the heat output will be
controlled either to high re or low re or, in the case of
modulating units, to any point between high and low re;
depending on the requirements of the space being heated
and the external controls tted.
3) Overheat Thermostat
This operates if high temperatures within the heater are
detected, the burners are turned o and a Red indicator
switch light on the front panel is illuminated. The fault
condition must be identied and rectied.
When the unit has cooled, push the Red indicator switch
inside the front panel to reset the limit thermostat interlock
relay, the red indicator light will go out and the unit is
operational again.
Note: The limit thermostat(s) can only be reset
once the unit has cooled down.
Unless the cause of the fault condition is
readily obvious, for example a power cut whilst
the heater was operating, a service engineer should be
contacted.
E) Maintenance
To maintain ecient, reliable and safe operation of the
heater it must serviced by a qualied person at least
annually and preferably at the end of the heating season.
If the heater has not been left operational
proceed as follows.
A) Checks before lighting the Air Heater
The following preliminary checks should be made before
lighting the heater(s)
a) Ensure that the ELECTRICAL supply to the heater is
switched OFF.
b) Check that all warm air delivery outlets are open.
c) Check that the thermostat is set at MAX.
d) Check that the clock control is set to an ON period.
e) Check that any other controls are calling for heat.
B) Lighting the Air Heater
1. Switch on the electrical supply at the isolator
2. If the Limit indicator light comes on press the limit
interlock reset switch inside the heater.
3. The startup sequence will commence. After a short
delay the burners will light and the green ‘ON’ indicator on
the front of the heater will be illuminated.
4. If the burners fail to light the control box will
automatically restart the ignition sequence. If after 5
attempts at ignition the burners have still failed to light
the control box will go to lockout and the Amber lockout
light on the front of the heater (or on the low level remote
reset, MC200 or Powrtrol RR if tted) will be illuminated. To
restart the ignition sequence depress the reset button on
the low level reset for about 1-2 seconds.
WARNING: If it is not possible to light the
heater after several attempts, contact the
installer or local service company.
C) To Shut Down the Air Heater
1) For Short Periods:
Turn the room thermostat to the OFF, or set to it’s lowest
setting.
2) For Long Periods:
Complete step 1 above. Wait for 5 minutes and then turn
OFF the electrical supply at the isolator.
User Instructions
