To Clean Outdoor Coil (Outdoor Unit); To Clean Condensate Drains; Service; Diagnostic Codes - Carrier 40QNB018 Installation, Start-Up And Service Instructions Manual

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REMOVE FILTER

To Clean Outdoor Coil (Outdoor Unit)

Some metal parts and sharp fins of outdoor unit coil can
cause personal injury during cleaning. Clean coil
carefully.
To clean the outdoor coil:
1. Remove any dirt or obstruction from discharge opening.
2. Use a garden hose to spray water on the coil. Debris that
collects between coil fins inhibits heat transfer — direct
the water spray between coil fins to flush out debris.
Cleaning Condensate Drains —
drain pans at the start of each cooling season. Check the flow
by pouring water into the drain.

SERVICE

When servicing unit, turn off all electric power to unit
to avoid shock hazard or injury from rotating parts.
Do not vent refrigerant to atmosphere when servicing
unit. Reclaim refrigerant during system repair or unit
removal.
Diagnostic Codes —
croprocessor control which continuously monitors the op-
eration of the unit. If an operational fault is detected, a fault
is indicated by the flashing of the green ''UNIT ON'' light
on the front of the fan coil unit. A red LED (light-emitting
diode) indicator light, located on the control board in the
control box of the indoor unit, will emit a flash code which
can be used to troubleshoot a system problem. The control
will continue to monitor the unit and, if the conditions which
cause the fault are cleared, the unit will return to normal
operation. If the fault code is present for 5 cycles of the unit,
the unit will be locked out and the alarm is indicated by the
flashing of the green ''UNIT ON'' light on the front of the
fan coil unit.
SET TIME
Fig. 22 — Setting The Current Time
Fig. 23 — Air Filter Maintenance
Clean all drains and
This unit is equipped with a mi-
VACUUM CLEAN
To access the LED indicator light, remove the front cover
of the unit by removing the 3 screws holding it in place.
If the LED indicator light continuously flashes on for one
second, then off for one second, the control is functioning
properly and no fault is present. A fast flashing LED indi-
cates that a fault has been detected. Table 7 lists the number
of quick flashes and the associated fault. If the system does
not operate, and the LED indicator does not flash, either the
power to the control board is off, or the control board has
failed.
System Tests —
formed continuously by the microprocessor. If a fault is
indicated, then the system allows only limited operation un-
til the problem is resolved. If the problem resolves itself,
then the code is cleared and operation resumes.
THERMISTOR TESTS — Each thermistor is tested for high
limit out of range (shorted condition) and low limit out of
range (open condition). If the thermistor is out of range, the
fault status indicator comes on and the LED flashes the ap-
propriate fault code.
Table 7 — System Fault Codes
NO. OF QUICK
LED FLASHES
2
3
4
5
6
7
8
9
LED — Light-Emitting Diode
*Heat pump systems only.
NOTE: If the LED light continuously flashes on for one second, then
off for one second, the control is functioning properly and no fault is
present.
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RINSE WITH WATER
System tests listed below are per-
SYSTEM FAULT
Room Air Thermistor
Indoor Coil Thermistor
Outdoor Coil Thermistor*
Compressor Malfunction
Reversing Valve Malfunction*
Outdoor Air Thermistor*
Indoor Fan Failure
Discharge Air Thermistor