Bard W60H1, W24H1, W18H1, W48H1, W36H1, W42H1 Solid State Heat Pump Control Troubleshootingprocedure

TROUBLESHOOTING

SOLID STATE HEAT PUMP CONTROL TROUBLESHOOTINGPROCEDURE

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.

NOTE: If there was no power to 24 volt transformer, the compressor and outdoor fan motor will not start for 5 minutes. This is because of the compressor short cycle protection.

		TABLE 1
		TROUBLESHOOTING
Symptom	Possible Causes	What & How to Check / Repair
Compressor will	Check for 24V from R to C	If 24V is not present at R, check wiring from board to transformer and check transformer input
not start (heating	on the heat pump control	and output voltage. If transformer has no 24V output, determine cause and replace
or cooling)		transformer.
	Check for 24V from Y to C	If 24V is not present, check thermostat and thermostat wiring, outdoor thermostat (if equipped)
	on low voltage terminal strip	phase monitor (if equipped, used on some 3-phase models). If 24V is present continue to
		next step.
	Check for 24V from C to	If 24V is present, check and/or replace compressor contactor. If 24V is not present, jump the
	CC on heat pump control	speed up terminal for 10 seconds. If compressor does not start check for 24V from C to L1
		on the heat pump control.
	Compressor lock out	If 24V is not present at L1 of the heat pump control, check the high pressure switch and low
		pressure bypass relay (if equipped) and all associated wiring and terminals. The safety circuit
		is a closed circuit. If the high pressure switch or low pressure bypass relay are open, the
		control will lock out the compressor. Replace defective component. Cycle power off and on to
		reset lock out. Jump speed up terminals for 10 seconds to override 5-minute time delay.
	Defective heat pump control	If 24V is present from C to Y, and C to L1 on the heat pump control, the time delay has been
		overridden or expired and no 24V is present at CC, replace the heat pump control.
Fan outdoor motor	Heat pump control defective	Check across fan relay on heat pump control. (Com-NC)
does not run		Replace heat pump control.
(cooling or heating
	Motor defective	Check for open or shorted motor winding. Replace motor.
except during
	Motor capacitor defective	Check capacitor rating. Check for open or shorted capacitor. Replace capacitor.
defrost)
Reversing valve	Heat pump control defective	Check for 24V between RV-C and B-C.
does not energize		1. Check control circuit wiring.
(heating only)		2. Replace heat pump control
	Reversing valve solenoid	Check for open or shorted coil.
	coil defective	Replace solenoid coil.
Unit will not go	Temperature sensor or heat	Disconnect temperature sensor from board and jumper across "SPEEDUP" terminals and "SEN
into defrost	pump control defective	JMP" terminals. This should cause the unit to go through a defrost cycle within one minute.
(heating only)		1. If unit goes through defrost cycle, replace temperature sensor.
		2. If unit does not go through defrost cycle, replace heat pump control.
Unit will not come	Temperature sensor or heat	Jumper across "SPEEDUP" terminal.
out of defrost	pump control defective.	This should cause the unit to come out of defrost within one minute.
(heating only)		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.

Manual	2100-511
Page	19 of 27