ECR RetroAire R90C Installation, operation & maintenance manual - page 24
Troubleshooting
WARNING
Fire, explosion, and electrical shock hazard. Troubleshooting procedures shall be conducted by a qualified
technician. Improper installation could result in death or serious injury.
!
Symptom
Suggestion
No heat or cooling
• Verify unit has power and thermostat is satisfied. If thermostat is not satisfied,
call your installing contractor or service contractor.
Thermostat calls for cooling, no
cool air is coming from unit.
• Verify continuity between thermostat and unit. Verify 24 Vac is present across
terminals
C
and
R
.
• Check outdoor coil for dirt debris, remove any foreign material. Locate high
pressure switch reset button and push button.
• Some units are equipped with
LCDI
(Leakage Current Detection Interrupt) line
cord. Verify line cord is reset by pressing reset button at line cord plug.
Note:
If evaporator fan is operational and above suggested procedures have been followed, and there is 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. Code determination:
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)
Circuit board light is blinking 3 or 4
times, there is no freeze condition.
(See Table 13, page 38)
• Verify sensors have not been damaged.
• Remove sensor wires from control board and take resistance measurements,
compare to following sensor resistances. Indoor and outdoor coil sensor wires
and control board are labeled.
• Verify sensors are correctly wired.
77°F = 10KOhms
50°F = 19.9KOhms
35°F = 30KOhms
30°F = 34.4KOhms
Thermostat is satisfied, fan is still
running.
• Thermostat set to Auto mode, once thermostat is satisfied, fan stays 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 stays energized regardless of
thermostat being satisfied or not. To turn fan off turn unit off or turn thermostat
fan switch to
AUTO
.
Thermostat calls for heat, no heat
comes from unit.
Units equipped with electric heaters have temperature limit switch to prevent electric
heater from reaching unsafe temperatures. After calling for heat, heater is not
energized, check for continuity across limit. If limit is open, replace with equivalent
limit switch. Auto reset / Manual reset Switch (Requires trained professional)
Thermostat calls for heat while in
heat pump mode, heated air is not
coming from 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.
• Verify
LCDI
line cord has not tripped.
• Verify thermostat while in heat pump mode 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 8, page 17.
• Verify there are no freeze conditions. See "Circuit board light is blinking" above
for more information.
TROUBLESHOOTING
The Right Fit for Comfort
24
P/N 240010330, Rev. A [10/15/2013]