Symptom
Suggestion
No heat or cooling
•
Check to see if unit has power and if thermostat is satisfied. If
thermostat is not satisfied, call your installing contractor or service
contractor.
Thermostat calls for cooling, but
cool air is not coming out of unit.
• Check for continuity between thermostat and unit. Verify 24Vac is
present across terminals C and R.
• Verify high pressure switch located in outdoor section has not been
tripped. If tripped, press switch button to restart compressor.
• Note: If evaporator fan is operational and all of above suggested
procedures have been followed, and there is still no cooling being
supplied by unit, contact trained heating and cooling professional.
Light on circuit board is
blinking.
• Circuit board uses light for diagnostic purposes. 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 cool units only)
Circuit board light is blinking 3
or 4 times, but there is no freeze
condition.
• Verify sensors have not been damaged. Remove sensor wires from control
board and make resistance measurements, compare to following sensor
resistances. Indoor and outdoor coil sensor wires are labelled, as is control
board.
–
77°F = 10KOhms
–
50°F = 19.9KOhms
–
35°F = 30KOhms
–
30°F = 34.4KOhms
Thermostat is satisfied, but fan
is still running.
•
If thermostat is set to auto mode, once thermostat is satisfied, fan will
stay energized for extra 60 seconds to purge unit of excess cool or warm
air in plenum.
• If thermostat fan switch is set to ON, fan will stay energized regardless
of whether thermostat is satisfied or not. Only way to turn fan off is to
turn unit off or turn thermostat fan switch to AUTO.
Thermostat calls for heat, but no
heat comes out of unit.
• Units equipped with electric heaters have temperature limit switch to
prevent electric heater from reaching unsafe temperatures. If after calling
for heating, heater is not energized, check for continuity across limit. If
limit is open, replace with equivalent limit switch.
Thermostat calls for heat while in
heat pump mode, but heated air
is not coming out of unit.
•
Verify unit has power or thermostat has been satisfied. If unit has power
and thermostat is satisfied, turn thermostat few degrees above room
temperature.
• While in heat pump mode, verify thermostat is not energizing O terminal.
Retroaire units are designed to work in heat pump mode when 24Vac
is present across Y and C. Verify heat pump jumper on control board
is jumping two pins labeled “HP”. See control board jumper locations,
Figure 11, Page 14.
• Verify there are no freeze conditions. Refer to blinking codes question
above for more information.
TROUBLESHOOTING
WARNING
Electrical shock hazard. Disconnect power to unit
before servicing or accessing control compartment.
Failure To follow these instructions could result in
death or serious injury.
!
NOTICE
Have qualified technician conduct troubleshooting
procedures.
18
Made in USA
PN 240010236 REV. D [12/15/2018]
