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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.
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.
Ignition Control Module
Electronic printed circuit board which sends and receives
voltages to various controls in an automatic ignition system.
An important safety feature of the control board is that it will
shut down the entire heater, thereby stopping the flow of
fuel gas if burner flame goes out.
Fan Housing
Chamber used for delivering 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).
Gas Control Valve
Electrical device consisting of a low pressure regulator and
electrical solenoids used for the control of gas flow to the
burner assembly. A feature of the control valve is it’s ability
to modulate from a first stage (minimum) heat position to a
second stage (maximum) heat position, if needed, to satisfy
the temperature requirements of the greenhouse. This
results in less temperature variation and potentially lower
fuel consumption.
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.
Hot Surface Igniter
Ignition device used on automatic ignition control systems.
Ignites gas by surface temperature rather than spark or
flame.
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.
Motor Relay
Electrical component wired between ignition control and
motor. Used to feed voltage to motor upon receipt of voltage
from ignition control.
Regulator
Mechanical device used in L.P. and natural gas distribution
systems to reduce a higher inlet pressure to a preset lower
pressure. The regulator is responsible to supply a steady
outlet pressure to the heater(s) despite changes in inlet
pressure, heater demand and weather conditions.
Selector Switch
Electrical device which is used to allow the end user to use
the heater in either a heating or ventilation application.
Thermostat
(Accessory)
A two stage electrical device which responds to more closely
match a heat to demand requirement. The thermostat
incorporates two independent control circuits which
interconnect to the heater’s two stage gas control valve,
thereby providing low or high heat depending on thermostat
setpoint.
Transformer
Electrical control used to accept line power supply primary
voltage and reduce it to lower secondary voltage to operate
certain control systems.
