9801ST00AMEN
20
SECTION 13. USER INSTRUCTIONS ST AIR HEATERS
SPECIAL NOTE
The following instructions have been written assuming that
the ST air heater is installed as a heating module
independent of being installed within an air handling
appliance. When installed within an air handling appliance or
as part of a multi-appliance/purpose system it will be
necessary to read any supplementary instructions in
conjunction with this document.
Operating
How the air heater works:
Gas is burned by an atmospheric burner which fires into a
heat exchanger. The gas burner is controlled by a double gas
valve via an electronic burner control, which is actuated
automatically via external controls i.e. a room thermostat
and/or a time switch. The burner is ignited by a hot surface
igniter. When the burner fires and warms the heat exchanger,
the heat is sensed by a thermally actuated fan control which
switches on the fan when the air temperature has reached its
preset operating level.
At the end of a heating cycle the burner is switched off, the
air circulation fan will continue to run until the air heater has
cooled to a safe condition. Thereafter the fan will remain off
until the next cycle is initiated.
Safety:
1. Flame failure is detected by the hot surface igniter which
is also the sensor and will immediately result in gas valve
shut down.
2. Safety against overheating is assured by two overheat
controls. The first is an automatic recycle control which
protects against low air flow i.e. clogged air ways, fan
failure etc. The second, which is set to a higher level than
the first one, is a control which locks out and switches off
the burner in the event of gross overheating for any
reason. Manual intervention is necessary to reset this
control device. Resetting of the automatic burner control
may also be required.
3. The location of the air heater should be maintained at
normal atmospheric pressure. Changes to the building
after air heater installation, should have regard to the
heating installation, i.e. structural changes causing
excessive draughts from doors, windows etc. Other air
handlers and installation of air extraction equipment which
may cause a negative pressure environment, can
seriously affect the operation of this type of air heater,
especially if combustion air supply is not ducted.
To light the heater:
1. Turn on the gas supply to the air heater.
2. Switch on the electricity supply to the air heater.
3. Ensure time switch (if fitted) is set to a 'ON' cycle.
4. Adjust control/room thermostat to desired
temperature.
5. Air heater will light automatically when the room
thermostat calls for heat.
6. If the appliance does not light:
a)
check that the burner control does not require
resetting. An indicator light glows at the front panel of
the appliance and on a remote control if fitted). Reset
by pushing light/button on appliance or the remote
control.
b)
check if thermal overheat control requires resetting
(see fig. 12 page 15 key 16).
7. If the thermal overheat control requires resetting and
doing so restarts the air heater, wait until the
appliance warms to thermal equilibrium, to ensure
the overheat control does not lock out again.
If it
does and the temperature near the heater is less
than 30
°
C, then switch off the appliance and call
for service.
If the temperature is over 30
°
C, take
appropriate action to reduce the ambient temperature
near the air heater.
Air
circulation:
1. The space heating process is for air to be circulated
through the appliance whereby it gains heat from a
heat exchanger. The air is directly discharged into the
space to be heated. The air is eventually recirculated.
Therefore it is very important that an unobstructed
path for the circulation of the air will be maintained.
This is particularly important if the air heater has
been installed to blow through the wall between two
rooms.
2. Sometimes the air circulation fan of the appliance is
connected to a remote over-ride switch. This enables
cool air to be used for circulation purposes when the
air heater is not used for heating purposes e.g. in
summer.
To use this feature:
a)
switch ON electricity
b)
switch ON manual override switch, this may be
fitted as a feature on a remote composite control.
Maintenance:
1. Maintenance and service must only be carried out by
appropriately qualified persons e.g. "Corgi" registered
undertakings.
2. It is in your interest to ensure service and
maintenance is carried out at regular intervals.
Periods between service are dependent upon the
local environment where the heater is installed. All
gas appliances should be serviced at least once a
year.
3. In case of any damage to the appliance, it must
be shut down completely and checked by an
appropriately qualified person.
4. In the event of difficulties in resolving any of these
matters, please do not hesitate to contact Ambi-Rad
or their official distributor.
