TM036 Vermont Gas Fireplace & Gas Log Fire Service Instructions REV: A
D.O.I: 17/01/2008
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7
Components and Their Function
Transformer
The transformer converts the incoming supply voltage from 240 VAC to 115VAC.
Fan
The fan moves air from outside the log fire through the back of the heater and out through
the front louvre via an air flow chamber. The air flow chamber is separated from the
combustion chamber and is heated by conduction. The heated air is then circulated by the
fan (convection heating). Fan speed may be controlled by the remote controller via the gas
valve which varies the voltage supply to the fan motor thus controlling the fan speed.
Secondary Flue
The secondary flue draws combustion gasses from the combustion chamber and vents
these gasses to atmosphere. Flue draw is created by an increase in temperature within the
flue due to the hot combustion gasses rising up the flue which simultaneously draws clean
air into the combustion chamber via the air intake louvres.
Blocked flue switch
A blocked flue switch is located in the flue section of each log fire. The blocked flue switch
is temperature sensitive and provides a safety shutdown function in the event of a blocked
flue by open circuiting the thermopile circuit and shutting down the gas valve. The blocked
flue switch comes pre-wired on the LHEC30 but is supplied separately for the RFSDV34
and
must
be installed and wired at time of installation (refer to wiring diagrams on page 6).
The blocked flue switch on the LHEC340 will automatically reset (close) when sufficiently
cool (<132ºC) however the blocked flue switch on the RFSDV34 is a manual reset type
and has a pin which is pushed to reset the switch. The reset switch can only be reset if the
switch temperature is less than 218ºC.
Pilot assembly
The pilot assembly is comprised of the pilot, ignition (spark) plug and two thermopiles.
Each component of the pilot assembly is detailed under its own separate heading.
Pilot
The pilot delivers gas from the gas valve which is then ignited by a spark from the ignition
plug. The burner is ignited by cross lighting from the pilot. The pilot
is a „permanent pilot‟
type. This means that the pilot is manually lit and remains on regardless of the burner
operation. The pilot can only be extinguished under normal operating conditions when the
log fire is manually turned off (pilotstat knob manually rotated to the
„off‟ position).
Ignition Plug
The ignition plug ignites the pilot gas by supplying a spark (high voltage) which arcs from
the ignition plug to the hood of the pilot (earth potential). The high voltage is generated by
the piezo igniter.
Thermopile
A thermopile is a group of thermocouples encased in a metal housing. The thermocouple
generates a voltage when heat is applied and the sum of the generated voltage is utilised
to electromagnetically hold open the pilot and burner gas valves; thus providing a safety
shut off in case of pilot flame failure. Each log fire has two thermopiles.
Burner Manifold
