29
Heater Component Function
Air Proving Switch
Safety device used to insure that the proper air flow is being
achieved before the gas valve is opened. (Model AB100
incorporates a paddle on the air-proving switch arm.)
Burner
Cast iron component used to channel gas and provide an
area at which the fuel may ignite.
Burner Orifice
Brass metering device used to feed gas to burner at a
specific rate.
Fan Housing
Chamber used for compressing air for efficient air
movement.
Fan Wheel
Component used in conjunction with the motor and fan
housing to pull the hot air from heater and blow it into room
for heating (also known as a squirrel cage).
Fuse
Safety device used to protect against an over amperage
condition which results from a direct electrical short.
Gas Hose
Flexible connector used to convey gas from supply line in
building to heater.
Heat Chamber
Metal “fire box” within the appliance that provides an area
where burner flame mixes with combustion air thereby
providing heat.
High Limit Switch
Safety device wired into the control system which is used to
break an electrical circuit to the gas control valve in event of
overheat situation.
Motor
Electric device used to force preheated air through the
heater and to circulate heat within a certain area. Converts
electrical energy into mechanical energy.
Pilot Light Orifice
A metering device used to supply gas for the dual purpose of
igniting the main burner and heating the thermocouple.
Pilot Safety Control Valve
A gas control valve which is held open by electrical power
supplied by a pilot generator and which closes automatically
to shut off the flow of gas to the main burner when the pilot
flame is extinguished or becomes too small to light the main
burner.
Pilot Shield
A formed sheet metal piece that fits around the pilot
assembly to protect the the pilot flame against drafts.
Pilot Tube
Formed copper tube used to convey gas from the safety
control valve to the pilot light orifice. The tube is internally
“tinned” when natural gas is used to resist the effects of
sulphur in the fuel.
Regulator
The heart of any gas supply installation. Used to deliver a
working pressure to the appliance under varying conditions
in tank pressure.
Sail (Flapper)
A formed piece of stainless steel located in the blower outlet
of the heater that pivots up with an increase in air pressure,
thereby engaging air flow switch. (Used on Model AB250.)
Throttle Valve
Manually adjustable component used to increase or
decrease the flow of gas to burner. The throttle valve is
located between gas control valve and burner assembly.
Thermocouple
A thermoelectric device that converts heat energy directly
into electrical energy. Works in conjunction with the
electromagnet in the gas control valve thereby providing gas
supply for the pilot light.
Thermostat
Electrical device used as an automatic “on/off” switch which
will respond to changes in temperature in a certain area.
Can be wired so contacts in the thermostat open or close on
temperature increase or decrease.
Transformer
Electrical control used to take higher incoming voltage and
reduce it to lower outgoing voltage to operate certain control
systems.
