Amana GUX-X Installation Instructions Manual page 22

CAUTION
The cause must be investigated by a
qualified servicer before any attempt is
made to engage the roll-out protection
device and turn the furnace back on.
ABNORMAL OPERATION - INTEGRATED IGNITION
CONTROL
The following presents the probable causes of question-
able furnace operation and how to fix them. Look through
the observation window in the blower access door and
make a note of the number of flashes in sequence between
pauses. Next, refer to the Timing Charts in Section IX for
an interpretation of the signals and to this section for a
description.
1. Internal Control Failure with Integrated Ignition
Control
An internal control failure occurs when the integrated
ignition control senses an internal problem and stops
the unit.
To solve this problem, replace the ignition control.
2. System Lockout
A system lockout occurs when the integrated ignition
control determines that a measurable combustion
cannot be established or maintained after three con-
secutive tries (four, if flame is established then lost) to
turn on the furnace.
If a flame is not sensed during the first six seconds after
a gas valve has been energized, the ignition control
will internally turn off the gas. After 60 seconds, during
which time the induced draft blower purges the heat
exchanger, the ignitor will re-energize and preheat for
27 seconds. The gas valve is then re-energized. If a
flame is not sensed again in six seconds, the gas valve
will de-energize and another purge is performed. The
ignition control will cycle the gas valve three times
before it determines it cannot establish measurable
combustion and enter a lockout state. If a flame is
sensed but lost after 10 seconds, the control will cycle
four more times before locking out. A lockout stops
ignition attempts and causes the air blower to run
continuously. The diagnostic light will indicate either
condition with one short flash followed by a longer off.
The control can be reset and brought out of lockout
mode by turning the thermostat off and then back on.
It can also reset by turning off the electrical disconnect
switch to the furnace for 30 seconds. The control will
reset after one hour.
IMPORTANT: If you have to frequently reset your furnace,
it means that a problem exists that should be corrected.
Contact a qualified servicer for further information.
3. Pressure Switch Stuck Closed
A sticking pressure switch can be caused by either a
faulty pressure switch, faulty wiring, a disconnected
hose, or a restricted intake or flue piping. In the case
of a pressure switch sticking closed, the probable
cause is a faulty pressure switch or wiring.
If the ignition control senses that the pressure switch
is closed and the induced draft blower is off, it will shut
down the unit until the fault is corrected. The light code
for this problem is two short flashes followed by a
longer pause.
4. Pressure Switch Stuck Open
A sticking open pressure switch can be caused by a
faulty pressure switch, a disconnected hose to the
pressure switch, a restricted air intake or flue piping, or
a faulty wiring.
If the ignition control senses that the induced draft
blower is energized but the pressure switch is not
closed, the control will keep the blower on and wait for
the switch to close. The diagnostic light code for this
problem is three short flashes followed by a pause.
5. Open Limit Control
An open limit control can be caused by a low condi-
tioned air flow due to dirty filter or resistance in duct
work, a faulty blower, a blower speed set too low, or a
faulty limit.
When the limit control opens, the induced draft and air
circulation blowers are turned on. The induced draft
blower will remain on for the first fifteen seconds of this
period. The air circulation blower will remain on until
the limit control is closed. The diagnostic light code for
this is four short flashes followed by a pause.
6. Open Rollout Control
An open rollout control is can be caused by insufficient
combustion air, a restricted flue passage, or a re-
stricted heat exchanger.
The opening of the rollout control signals the air
circulation blower and the induced draft blower to turn
on. The air circulation blower will remain on until the
limit is manually reset. The induced draft blower will
remain on for the first fifteen seconds of this period.
The diagnostic light code for this is five short flashes
followed by a pause.
7. Flame Sensed with No Call for Heat
If the control senses a flame when the gas valve is de-
energized, it will run the air circulation blower and the
induced draft blower continuously. The diagnostic light
code for this is continuous light flashing. Probable
cause is miswiring.
OPERATING INSTRUCTIONS
1. Close the manual gas valve external to the furnace.
2. Turn off the electrical power supply to the furnace.
3. Set room thermostat to lowest possible setting.
4. Remove the louvered door on the front of the furnace
by turning the latch screw 1/4 turn.
NOTE: This furnace is equipped with an ignition device
which automatically lights the burner. Do not try to light
burner by hand.
5. White Rodgers Model 36E36 or 36E37 or Honeywell
Model VR-8205: Turn the gas control knob clockwise
to the OFF position.
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