Symptoms
Possible Cause
Check/Remedies
13. Unit does not operate
Check power supply, blown fuse,
tripped circuit breaker or blower
door switch
Check cause and correct
Polarity of incoming power incorrect
Check polarity of incoming electrical
power leads and correct
Loose electrical connections
Tighten all connections
Failed thermostat
Replace
Failed transformer
Check both primary and
secondary; replace transformer
if necessary
Failed pressure switch
Test and replace if necessary
Pilot flame outage
Test and repair if necessary; see
"Pilot Outage" (#3)
Gas shut off
Check gas valves
Gas valve inoperative
Test and replace if necessary
Restriction in vent
Check for improper vent length,
too many elbows, blockage or
incorrect elbows
Inducer motor not properly operating
Test and replace if necessary
Leaking inducer housing gasket Replace gasket
Integrated furnace control (IFC)
malfunctioning
Test and replace if necessary
Open over temperature switch
Determine cause and reset
14. Uneven temperatures
Air distribution system not balanced
Balance system by adjusting
dampers
Thermostat location
See "Installing Thermostat" in
installation instructions
Oversized unit
Check heat load calculation
15.
Burner does not maintain
flame
Incorrect gas input
Clock gas meter and
determine input
Overtired furnace
Replace orifice and adjust
pressure within limitations
Igniter malfunction
Adjust, replace igniter
Incomplete combustion
Check for sufficient combustion
air or blockage
Improper unit ground
Chec!</repair ground connection
Polarity of incoming electrical
power incorrect
Check and correct
16. Soot in heat exchanger
Improper fueVair mixture,
orifice oversized
Check/adjust gas pressure;
check combustion air;
check orifice size table
Insufficient combustion air Check and increase
combustion air
17. System starts up, cycles four
times and locks out
(Electronic Ignition only)
Low gas pressure Test gas supply and correct
as necessary
Gas valve in "OFF" position Place gas valve manual control
in "ON" position
Polarity reversed
Reverse main power leads
in "J" box
Malfunctioning igniter Replace igniter; check resistance
of igniter
Sensor contaminated
Clean with steel wool and recheck
Sensor out of position
Adjust bracket and recheck
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