Troubleshooting; Solid State Heat Pump Control; Table 3 Troubleshooting - Bard C24H1 Series Installation Instructions Manual

TROUBLESHOOTING

SOLID STATE HEAT PUMP CONTROL

TROUBLESHOOTING PROCEDURE
1. NOTE: A thorough understanding of the defrost
cycle sequence is essential. Review that section
earlier in this manual prior to troubleshooting the
control. Turn on AC power supply to unit.
2. Turn thermostat blower switch to "fan on" – the
indoor blower should start. (If it doesn't,
troubleshoot indoor unit and correct problem.)
3. Turn thermostat blower to "auto" position. Indoor
blower should stop. NOTE: Many models have a
1-minute blower time delay on "off" command;
wait for this to time-out.
4. Set system switch to "heat" or "cool". Adjust
thermostat to call for heat or cool. The indoor
blower, compressor and outdoor fan should start.
Symptom Description, Check & Possible Causes
Compressor will 1. Check for LED illumination.
Is there an LED illuminated on the board (flashing)?
not start (heating
or cooling)
2. Check for error codes.
Is the LED flashing a Code?
3. Check for power at board.
Is there 24 volts AC between R and C?
4. Check codes.
What code is blinking?
5. Compressor delay active.
Wait for 5 minute delay or jump board's "speed up pins".
6. Low pressure fault.
7. High pressure fault.
8. Check for Compressor input signal.
Is there 24 volts AC between Y and C?
9. No power to board.
10. Check for Compressor output signal.
Is there 24 volts AC between CC & C?
11. No "Y" compressor input signal.
12. No "CC" compressor output signal.
13. Faulty board.
Fan outdoor motor
Heat pump control defective
does not run
(cooling or heating
Motor defective
except during
Motor capacitor defective
defrost)
Reversing valve
Heat pump control defective
does not energize
(heating only)
Reversing valve solenoid coil defective
Unit will not go
into defrost
Temperature sensor or heat pump control defective
(heating only)
Unit will not come
out of defrost
Temperature sensor or heat pump control defective
(heating only)
Manual 2100-586B
Page 18 of 25
NOTE: If there was no power to 24 volt transformer,
BLINK
Slow
Fast
1
2
3
4

TABLE 3 TROUBLESHOOTING

Yes = go to Step #2; No = go to Step #
Yes = go to Step #4; No = go to Step #8
Yes = go to Step #13; No = go to Step #9
Code "1", go to Step #6; Code "2", go to Step#7; Fast Blink, go to Step #5
Check for proper operation; if still needed, go back to Step #1.
Check wiring circuit and unit pressures.
Check wiring circuit and unit pressures.
Yes = go to Step #10; No = go to Step #11
The unit either does not have unit voltage, the transformer is bad or the unit
wiring is incorrect.
Yes = go to Step #12; No = go to Step #13
Check thermostat wiring, incorrect phase of unit (see section on Phase Monitor),
and finally unit wiring.
Check compressor contactor for proper operation and finally check compressor.
Replace defrost board.
Check across fan relay on heat pump control. (Com-NC)
Replace heat pump control.
Check for open or shorted motor winding. Replace motor.
Check capacitor rating. Check for open or shorted capacitor. Replace capacitor.
Check for 24V between RV-C and B-C.
1. Check control circuit wiring.
2. Replace heat pump control.
Check for open or shorted coil.
Replace solenoid coil.
Disconnect temperature sensor from board and jumper across "SPEEDUP"
terminals and "SEN JMP" terminals. This should cause the unit to go through a
defrost cycle within one minute.
1. If unit goes through defrost cycle, replace temperature sensor.
2. If unit does not go through defrost cycle, replace heat pump control.
Jumper across "SPEEDUP" terminal.
This should cause the unit to come out of defrost within one minute.
1. If unit comes out of defrost cycle, replace temperature sensor.
2. If unit does not come out of defrost cycle, replace heat pump control.
the compressor and outdoor fan motor will
not start for 5 minutes. This is because of
the compressor short cycle protection.
LED BLINK CODES
FUNCTION
Normal function (1.0 sec on/1.0 sec off)
ASCD timer active (0.1 sec on/0.1 sec off)
Low pressure switch failure
High pressure switch failure/"Soft" Lockout
Defrost mode active
High pressure switch failure/"Hard" Lockout
What & How to Check / Repair