Goodman Mfg GPG13 - Manual (Page 16)

16
A
BNORMAL
O
PERATION
- H
EATING
Internal Control Failure
If the integrated ignition control in this unit encounters an
internal fault, it will go into a “hard” lockout and turn off the
diagnostic LED. If diagnostic LED indicates an internal fault,
check power supply to unit for proper voltage, check all fuses,
circuit breakers and wiring. Disconnect electric power for five
seconds. If LED remains off after restoring power, replace
control.
External Lockout
An external lockout occurs if the integrated ignition control
determines that a measurable combustion cannot be
established within three (3) consecutive ignition attempts. If
flame is not established within the seven (7) second trial for
ignition, the gas valve is deenergized, 15 second inter-purge
cycle is completed, and ignition is reattempted. The control
will repeat this routine three times if a measurable combustion
is not established. The control will then shut off the induced
draft blower and go into a lockout state.
If flame is established but lost, the control will energize the
circulator blower at the heat speed and then begin a new ignition
sequence. If flame is established then lost on subsequent
attempts, the control will recycle for four (4) consecutive
ignition attempts (five attempts total) before locking out.
The diagnostic fault code is 1 flash for a lockout due to failed
ignition attempts or flame dropouts. The integrated control
will automatically reset after one hour, or it can be reset by
removing the thermostat signal or disconnecting the electrical
power supply for over five seconds. If the diagnostic LED
indicates an external lockout, perform the following checks:
• Check the supply and manifold pressures
• Check the gas orifices for debris
• Check gas valve for proper operation
• Check secondary limit
A dirty filter, excessive duct static, insufficient air flow, a
faulty limit, or a failed circulator blower can cause this
limit to open. Check filters, total external duct static,
circulator blower motor, blower motor speed tap (see
wiring diagram), and limit. An interruption in electrical
power during a heating cycle may also cause the
auxiliary limit to open. The automatic reset secondary
limit is located on top of the circulator blower assembly.
• Check rollout limit
If the burner flames are not properly drawn into the heat
exchanger, the flame rollout protection device will open.
Possible causes are restricted or blocked flue passages,
blocked or cracked heat exchanger, a failed induced
draft blower, or insufficient combustion air. The rollout
protection device is a manual reset limit located on the
burner bracket. The cause of the flame rollout must be
determined and corrected before resetting the limit.
• Check flame sensor
A drop in flame signal can be caused by nearly invisible
coating on the sensor. Remove the sensor and carefully
clean with steel wool.
• Check wiring
Check wiring for opens/shorts and miswiring.
Important: If you have to frequently reset your gas/electric
package unit, it means that a problem exists that should be
corrected. Contact a qualified servicer for further
information.
Pressure Switch Stuck Open
A pressure switch stuck open can be caused by a faulty
pressure switch, faulty wiring, a disconnected or damaged
hose, a blocked or restricted flue, or a faulty induced draft
blower.
If the control senses an open pressure switch during the pre-
purge cycle, the induced draft blower only will be energized. If
the pressure switch opens after ignition has begun the gas
valve is deenergized, the circulator blower heat off cycle begins,
and the induced draft blower remains on. The diagnostic fault
code is two flashes.
Pressure Switch Stuck Closed
A stuck closed pressure switch can be caused by a faulty
pressure switch or faulty wiring. If the control encounters a
pressure switch stuck closed, the induced draft blower remains
off. The diagnostic LED code for this fault is three (3) flashes.
Open Thermal Protection Device
If the primary limit switch opens, the gas valve is immediately
deenergized, the induced draft and air circulating blowers are
energized. The induced draft and air circulator blowers remain
energized until the limit switch recloses. The diagnostic fault
code for an open limit is four (4) flashes.
A primary limit will open due to excessive supply air
temperatures. This can be caused by a dirty filter, excessive
duct static, insufficient air flow, or a faulty limit. Check filters,
total external duct static, blower motor, blower motor speed
tap (see wiring diagram), and limit. This limit will automatically
reset once the temperature falls below a preset level.
Flame Detected with Gas Valve Closed
If flame is detected with the gas valve deenergized, the
combustion and air circulator blowers are energized. The
diagnostic fault code is five (5) flashes for this condition. The
control can be reset by removing the power supply to the unit
or it will automatically reset after one hour. Miswiring is the
probable cause for this fault.
A BNORMAL O PERATION - C OOLING
Short Cycle Compressor Delay
The automatic ignition control has a built-in feature that
prevents damage to the compressor in short cycling
situations. In the event of intermittent power losses or
intermittent thermostat operation, the ignition control will delay
output to the compressor contactor for three minutes from the
time power is restored. (Compressor is off a total of three
minutes). The diagnostic LED will flash six (6) times to indicate
the compressor contactor output is being delayed.
NOTE: Some electronic thermostats also have a built-in
compressor short cycle timer that may be longer than the three
minute delay given above. If you are using an electronic thermostat
and the compressor has not started after three minutes, wait an
additional five minutes to allow the thermostat to complete its short
cycle delay time.