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FURNACE - ELECTRONIC IGNITION Model (continued)
Effective: 8/10/98
CAUSE
SOLUTION
S O O T I N G ( c a u s e d b y l a z y y e l l o w f l a m e )
Low gas pressure
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*Set pressure to a minimum of 11˝ W.C. with all appliances
running. Replace regulator if not obtainable.
Low voltage
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Correct power supply*
Air leakage at gaskets
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Replace gaskets
Combustion wheel installed backwards or loose
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Reposition wheel and tighten.
Blockage in heating chamber or burner head
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Clean or replace
Faulty motor
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Replace motor
Wrong vent kit or draft cap
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Replace with correct vent kit or draft cap
FAN RUNS CONTINUOUSLY WITH THERMOSTAT “OFF”
Defective thermostat
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Replace thermostat
Shorted thermostat leads
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*Replace wire or wires
Defective relay
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Replace relay
L I M I T I N G = B U R N E R C Y C L I N G O N A N D O F F - BLOWER RUNS CONSTANTLY WITH THERMOSTAT ON
Restricted or insufficient discharge ducting
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a. Ducting must meet furnace’s minimum requirements.*
b. No excess ducting or unnecessary bends.*
c. All closeable registers must be fully open and unrestricted.*
Furnace over fired
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Set gas pressure to a minimum of 11˝ W.C. with all appliances
running replace regulator, if not obtainable. Also, check main
burner orifice, it must comply with furnace’s specifications.*
Restricted return air supply
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Make sure return air meets furnace minimum requirements.*
Defective limit switch
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Replace limit switch
B L O W E R S H U T S O F F AT S A M E T I M E B U R N E R S H U T S O F F
Wired wrong
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*Correct wiring
Faulty relay
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Replace relay.
B L O W E R V I B R AT E S O R I S N O I S Y
Motor mount loose
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Tighten motor mounting bracket
a. Ducting must meet furnace’s minimum requirements*
b. No excess ducting or unnecessary bends.*
c. All closeable registers must be fully open and unrestricted.
Damaged blower wheel
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Replace blower wheel.
Motor shaft bent
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Replace motor
I N S U F F I C I E N T H E AT
Furnace under fired
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1. Set gas pressure to 11˝ W.C. with all appliances running,
replace regulator if not obtainable. Also, check main burner
orifice, it must comply with furnace’s specifications.
2. Check ducting and return air according to furnaces
specifications.*
Furnace improperly sized for coach/or conditions
----
Replace furnace with proper size.