Maintenance & Troubleshooting
(continued)
Troubleshooting
WARNING
The troubleshooting procedures below should only be conducted by a qualified technician.
Symptom
Suggestion
No heat or cooling
Check to see if the unit has power and if the thermostat is satisfied. If the thermostat is not
•
satisfied, call your installing contractor or service contractor.
The thermostat calls for cooling, but cool air
is not coming out of the unit.
Check for continuity between the thermostat and the unit. Also make sure 24 Vac is present
•
across terminals
C
and
R
.
Check outdoor coil for dirt debris, remove any foreign material. Locate the high pressure
•
switch reset button and push button.
Some units are equipped with an
•
LCDI
(Leakage Current Detection Interrupt) line cord.
Make sure this line cord is reset by pressing the reset button at the line cord plug.
Note: If the evaporator fan is operational and all of the above suggested procedures have
•
been followed, and there is still no cooling being supplied by the unit, then contact a trained
heating and cooling professional.
A light on the circuit board is blinking.
The circuit board uses this light for diagnostic purposes. The blinking codes are as follows:
•
1 blink = normal operation
•
2 blinks = compressor lockout (
•
ASCT
— Anti-Short Cycle Timer)
3 blinks = outdoor freeze condition
•
4 blinks = indoor freeze condition
•
5 blinks = simultaneous
•
Y
and
W
call (Straight cooling units only)
The circuit board light is blinking 3 or 4
times, but there is no freeze condition. (see
table 1 p.31)
Make sure the sensors have not been damaged. Remove sensor wires from the control board
•
and make resistance measurements, then compare them to the following sensor resistances.
Indoor and outdoor coil sensor wires are labelled, as is the control board. Make sure the
sensors are correctly wired?
77°F = 10KOhms
•
50F = 19.9KOhms
•
35F = 30KOhms
•
30F = 34.4KOhms
•
The thermostat is satisfied, but the fan is still
running.
If the thermostat is set to auto mode, once the thermostat is satisfied, the fan will stay ener-
•
gized for an extra 60 seconds to purge the unit of excess cool or warm air in the plenum.
If the thermostat fan switch is set to
•
ON
, the fan will stay energized regardless of whether
the thermostat is satisfied or not. The only way to turn the fan off would be to turn the unit
off or to turn the thermostat fan switch to
AUTO
.
The thermostat calls for heat, but no heat
comes out of the unit.
Units equipped with electric heaters have a temperature limit switch to prevent the electric
•
heater from reaching unsafe temperatures. If after calling for heating the heater is not ener-
gized, check for continuity across the limit. If the limit is open, replace it with an equivalent
limit switch. Auto reset / Manual reset Switch (Requires trained professional)
The thermostat calls for heat while in heat
pump mode, but heated air is not coming
out of the unit.
Check to see if the unit has power or if the thermostat has been satisfied. If the unit has
•
power and the thermostat is satisfied, turn the thermostat a few degrees above room tem-
perature.
Make sure the
•
LCDI
line cord has not tripped. (See Page 9 for information.)
While in heat pump mode, make sure the thermostat is not energizing the
•
O
terminal. Ret-
roAire units are designed to work in heat pump mode when 24vac is present across
Y
and
C
.
Also, make sure the heat pump jumper on the control board is jumping the two pins labeled
“
HP
” (see control board jumper locations, Figure 10, page 16 and discussion).
Make sure there are no freeze conditions. Refer to blinking codes question above for more
•
information.
Replacement Packaged Terminal Air-Conditioning / Heat Pump
• Installation, Operation, and Maintenance Manual •
P/N 240008639, Rev. B [8/16/2011]
23
Made in USA