Operating instructions

15
Secondary Limit Control figure).
If the burner flames are not properly drawn into the heat
exchanger, the flame rollout protection device will open. The
rollout limit 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. Possible causes are restricted or
blocked flue passages, blocked or cracked heat exchanger, a
failed induced draft blower, or insufficient combustion air.
Important: If a limit opens five (5) times within a single
call for heat, the ignition control will go into a 30-minute lockout.
Only the air circulator blower remains on during this lockout.
The diagnostic fault code for this condition is “8” flashes and
the control automatically resets after 30 minutes. A dirty filter is
the most likely cause for the fault.
Flame Detected with Gas Valve Closed
If flame is sensed 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.
Low Flame Sensor Current
If the flame sense current drops below approximately one
microamp DC, the diagnostic LED will flash seven (7) times.
The control will function normally until it can no longer sense
flame. If this fault code is encountered, have a qualified service
technician remove the sensor and clean it with steel wool.
Gas Valve Energized When It Should Be OFF
Some models utilize an ignition control that recognizes voltage
present at the gas valve when the gas valve should be off. If
the ignition control senses this fault, it will lockout all functions
except continuous fan. This fault is indicated by (9) flashes.
Possible causes are miswiring, shorts in the wire harness, or
corrosion at the burners. Check and correct wiring if required.
Inspect and clean burners if required. Power to the unit must
be removed in order to reset the control from lockout.
ABNORMAL OPERATION - COOLING
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.
MAINTENANCE
Have the gas heating section of the unit checked at least once
a year before the heating season begins, to be sure that the
combustion air inlet and flue outlet hoods are not blocked by
debris, which would prevent adequate combustion air and a
properly operating vent system.
WARNING
T
O AVOID PERSONAL INJURY OR DEATH DUE TO ELECTRIC SHOCK,
DISCONNECT ELECTRICAL POWER BEFORE PERFORMING ANY MAINTENANCE.
REPLACING OR CLEANING FILTER
A return air filter is not supplied with this unit; however, there
must be a means of filtering all of the return air. The filter(s)
may be located in the return air duct(s), or return air filter grille(s).
Consult with your installing dealer for the actual location of the
return air filter(s) for your unit.
Dirty filters are the most common cause of inadequate heating
or cooling performance. Filter inspection should be made at
least every two months; more often if necessary because of
local conditions and usage.
Dirty throwaway filters should be discarded and replaced with a
new, clean filter. Dirty permanent filters should be washed with
water, thoroughly dried and sprayed with a filter adhesive before
being reinstalled. (Filter adhesives may be found at many
hardware stores.) Permanent filters should last several years.
However, should one become torn or uncleanable, it should be
replaced.
IGNITION CONTROL DIAGNOSTIC INDICATOR CHART
Light Signal Refer to Abnormal Heating or Cooling Operation Sections of this Manual
Off Internal Lockout
1 Flash External Lockout
2 Flashes Pressure Switch Stuck Open
3 Flashes Pressure Switch Stuck Closed
4 Flashes Open Thermal Protection Device
5 Flashes Flame Sensed with Gas Valve Closed
6 Flashes Short Cycle Compressor Delay (Cooling)
7 Flashes Low Flame Sense Current
8 Flashes Thermal Protection Device Open
9 Flashes Gas Valve Energized When It Should Be OFF (DSI-1 Control Only)