OPERATING THE SYSTEM WITH QT CONTROLS
Blizzard
Tur
bo Split System Manual
22
L-3448 ENGLISH
F
AULT
S
HUTDOWNS
AND
E
RROR
M
ESSAGES
When power is lost, the system will begin operating in the previous mode prior to power loss. All program values are retained in
a non-volatile memory.
The Qt Control/Display contains built-in safeguards designed to protect the air conditioning system from damaging conditions. If
an operational failure occurs, the Qt Control/Display will flash one of the following code messages. Fault or error code displays
are cancelled by pressing the MODE key. (See Table 3 and Table 4.)
NOTE 1: If user selects HEAT or COOL mode, unit will operate and the display will flash “Error Code” until the MODE
key is pressed. After the MODE key is pressed, display will show steady "—" until fault is corrected.
If user selects AUTO mode, unit will shut down until MODE key is pressed. Display will show “—” and unit will run.
NOTE 2: If an “Error Code” is displayed, the MODE key may be pressed to continue operating the unit until the sensor
is repaired. Fault code shutdown must be corrected before operation is allowed to continue.
Table 3: FAULT CODE CHART
Table 4: ERROR CODE CHART
FAULT CODE DISPLAY
MODES
COMMENT
“LO” then “AC”
Low voltage shutdown
See AC line voltage calibration section
“HI” then “AC”
High voltage shutdown
See AC line voltage calibration section
“LO” then “FC”
Low frequency shutdown
Incoming frequency < 57 Hz. Adjust power
source output frequency to 60 Hz with unit
operating in COOL mode.
“HI” then “FC”
High frequency shutdown
Incoming frequency > 63 Hz. Adjust power
source output frequency to 60 Hz with unit
operating in COOL mode.
“HI” then “PS”
High pressure shutdown
(compressor running)
Head pressure above 425 psi during cooling
operation. Check to see if condenser fan is
operating properly.
“HI” then “—”
High pressure shutdown
(compressor off)
High pressure switch or wiring has “failed open”
during cooling operation. Replace high pressure
switch or check high pressure switch wiring for
an “open circuit.”
ERROR CODE DISPLAY
MODES
COMMENT
“IS” then “—”
Internal temperature sensor error
Replace internal temperature sensor with cable.
See note 1 above.
“CS” then “—”
(ignore during heating mode)
Compressor discharge temperature
sensor fail
Replace compressor discharge temperature
sensor and cable. See note 1 above.
“—” (steady)
Mode button has been pressed to
run unit after an “Error Code.”
Unit running after a sensor failure. See note 2
above.
“LO” then “ES”
Evaporator sensor shutdown
Shutdown due to evaporator icing in COOL
mode. Evaporator sensor temperature < 34°F.
De-ice the evaporator by running the internal fan
only in manual mode.
“ES” then “—”
Evaporator temperature sensor
Failed or shorted evaporator temperature
sensor. Replace evaporator temperature sensor
and cable. See note 1 above.
