Goodman ACVC8 CA Series AMVC8 CA Series Service And Troubleshooting page 48

TROUBLESHOOTING
Sym ptom s of Abnorm al
Ope ration
• Induced draft blow er and
circulator blow er runs
continuously. No furnace
operation.
• Integrated control module LED
display provides error code.
• No furnace operation.
• Integrated control module LED
display provides error code.
• Normal furnace operation.
• Integrated control module LED
display provides error code.
• Furnace fails to operate.
• Integrated control module LED
display provides error code.
• Furnace fails to operate on
high stage; furnace operates
normally on low stage.
• Integrated control module LED
display provides error code.
• Furnace fails to operate on
high stage; furnace operates
normally on low stage.
• Integrated control module LED
display provides error
code.
• Furnace fails to operate.
• Integrated control module LED
display provides error code.
• Furnace fails to operate.
• Integrated control module LED
display provides error code.
48
Diagnos tic /
Status LED Fault Description
Codes
• Flame sensed w ith
no call for heat.
• Open Fuse
• Flame sense micro
amp signal is low
• Problem w ith igniter
circuit.
• High stage pressure
sw itch circuit is
closed at start of
heating cycle.
• Induced draft
blow er is operating.
• Furnace is
operating on low
stage only
• High stage pressure
sw itch circuit is not
closed.
• Induced draft
blow er is operating.
• Furnace is
operating on low
stage only
• Polarity of 115 volt
AC is reversed
• Gas valve is not
energized w hen it
should be.
• External Gas Valve
Error
Possible Cause s
• Short to ground in fame • Correct short at fame sensor or
sense circuit. in fame sensor w iring.
• Lingering burner fame. • Check for lingering fame.
• Slow closing gas valve. • Verify proper operation of gas
valve.
• Short in low voltage • Locate and correct short in low
w iring voltage w iring
• Flame sensor is • Clean flame sensor if
coated/oxidized. coated/oxidized.
• Flame sensor incorrectly • Inspect for proper sensor
positioned in burner fame. alignment.
• Lazy burner fame due to • Check inlet air piping for
improper gas blockage, proper length, elbow s,
pressure or combustion air. and termination.
• Compare current gas pressure to
rating plate. Adjust as needed.
• Improperly connected • Check and correct w iring from
igniter. integrated control module to igniter.
• Shorted igniter. • Replace shorted igniter.
• Poor unit ground.
• Check and correct unit ground
• Igniter relay fault on w iring.
integrated control module. • Check igniter output from control.
Replace if necessary.
• High stage pressure • Replace high stage pressure
sw itch contacts sticking.
sw itch.
• Shorts in pressure sw itch • Repair short in w iring
circuit w iring.
• Pressure sw itch hose • Inspect pressure sw itch hose.
blocked pinched, or Repair/replace if necessary.
connected improperly. • Inspect fue and/or inlet air piping
• Blocked fue and/or inlet air for blockage, proper length,
pipe, blocked drain system elbow s, and termination. Check
or w eak induced draft drain system. Correct as
blow er. necessary.
• Incorrect pressure sw itch • Check induced draft blow er
set point or malfunctioning performance. Correct as
sw itch contacts. necessary.
• Loose or improperly • Correct pressure sw itch set
connected w iring. point or contact motion.
• Tighten or correct w iring
connection.
• Polarity of 115 volt AC • Review w iring diagram to correct
pow er to furnace or polarity.
integrated module is • Verify proper ground. Correct if
revered. necessary.
• Poor unit ground • Check and correct w iring.
• Misw ired gas valve circuit • Check w iring in gas valve circuit
• Open gas valve circuit • Replace integrated control board
• Gas valve relay on
integrated control board
stuck open
Corrective Actions
• Turn pow er OFF prior to
repair.
• Turn pow er OFF prior to
repair.
• Replace fuse w ith 3-amp
automotive type
• Turn pow er OFF prior to
repair.
• Clean flame sensor w ith
steel w ool.
• See "Vent/Flue Pipe"
section for piping details.
• See rating plate for proper
gas pressure.
• Turn pow er OFF prior to
repair.
• Replace igniter w ith correct
replacement part.
• Replace control w ith
correct replacement part.
• Turn pow er OFF prior to
repair.
• Replace pressure sw itch
w ith proper replacement part.
• Turn pow er OFF prior to
repair.
• Replace pressure sw itch
w ith proper replacement part.
• Replace induced draft
blow er w ith proper
replacement part.
• Turn pow er OFF prior to
repair.
• Turn pow er OFF prior to
repair.
Notes & Cautions