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2. If ignition does not occur on the first trial,
the gas and spark are shut-off by the ignition
control and the control enters an inter-purge
period of 45 seconds, during which the draft
inducer continues to run.
3. At the end of the inter-purge period,
another trial for ignition will be initiated.
4. Control will initiate up to three ignition
trials on a call for heat before lockout of
control occurs.
5. Control can be brought out of lockout by
either removing power from the control for
more than 1 second or setting the thermostat
to its lowest position and waiting 5 seconds
and then turning back up to call for heat.
Some controls provided will automatically
reset after one hour and initiate a call for heat.
Burner Flames
Prior to completing the start-up, check the
appearance of the main burner flame for
flame characteristics of properly adjusted
natural gas systems.
1. The burner flame should be predominately
blue in color and well defined and centered at
the tube entry. Distorted flame or yellow
tipping of natural gas flame, may be caused
by lint and dirt accumulation inside burner or
at burner ports, at air inlet between burner
and manifold pipe, or debris in the main
burner orifice. Soft brush or vacuum clean
affected areas after performing Shutdown
procedure.
Figure 39 - Natural Gas Flame
Figure 40 - Propane Gas Flame
2. Poorly defined, substantially yellow
flames, or flames that appear lazy, indicate
poor air supply to burners or excessive burner
input. Verify gas supply type and manifold
pressure with rating plate.
3. Poor air supply can be caused by
obstructions or blockage in heat exchanger
tubes or vent discharge pipe. Inspect and
clean as necessary by to eliminate blockage.
Vacuum any dirt or loose debris found in the
tubes or vents. Clean heat exchanger tubes
with stiff brush after performing Shutdown
procedure. Poor flame characteristics can
also be caused by undersized combustion air
openings or flue gas recirculation into
combustion air supply. Increase air opening
size or re-direct flue products to prevent re-
circulation.
4. Reduced air delivery can also be the result
of fan blade slippage, dirt accumulation the
fan blade or low voltage to draft inducer
motor. Inspect draft fan assembly and be sure
fan blade is secure to motor shaft. Check line
voltage to heater.
Do not store or use gasoline or other
flammable vapors and liquids in the
vicinity of this or any other appliance.
WARNING
Yellow Color is
ONLY allowed
at the tip of the
flame