Daikin DCG Series Installation And Maintenance Manual page 25

• 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 pres-
sure 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 (3 FLASH CODE)
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 en-
ergized. The induced draft and air circulator blowers remain en-
ergized 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, insuffi-
cient 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.
(2 FLASH CODE)
(4 FLASH CODE)
Flame Detected with Gas Valve Closed
If flame is detected with the gas valve deenergized, the combus-
tion 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 O - C
BNORMAL PERATION OOLING
Short Cycle Compressor Delay (6 FLASH CODE)
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 de-
layed.
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.
T
O PREVENT UNRELIABLE OPERATION OR EQUIPMENT DAMAGE
GAS MANIFOLD PRESSURE MUST BE AS SPECIFIED ON THE UNIT RATING
. O
PLATE NLY MINOR ADJUSTMENTS SHOULD BE MADE BY ADJUSTING
THE GAS VALVE PRESSURE REGULATOR
23
(5 FLASH CODE)
C
ODES
CAUTION
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