Carrier 25HPA6 instruction manual Status Codes, Troubleshooting

Status Codes

Table 4 shows the status codes flashed by the amber status light. Most system problems can be diagnosed by reading the status code as flashed by the amber status light on the control board.

The codes are flashed by a series of short and long flashes of the status light. The short flashes indicate the first digit in the status code, followed by long flashes indicating the second digit of the error code.

The short flash is 0.25 seconds ON and the long flash is 1.0 second ON. Time between flashes is 0.25 seconds. Time between short flash and first long flash is 1.0 second. Time between code repeating is 2.5 seconds with LED OFF.

EXAMPLE:

3 short flashes followed by 2 long flashes indicates a 32 code. Table 4 shows this to be low pressure switch open.

Table 4 – TROUBLESHOOTING

OPERATION		AMBER LED
	FAULT	FLASH	POSSIBLE CAUSE AND ACTION
		CODE
Standby – no call for unit operation	None	On solid, no	Normal operation
		flash
Low Stage Cool/Heat Operation	None	1, pause	Normal operation
High Stage Cool/Heat Operation	None	2, pause	Normal operation
	System Commu-	16	Communication with User Interface lost. Check wiring to User Interface,
	nications Failure		indoor and outdoor units
	Invalid Model Plug	25	Control does not detect a model plug or detects an invalid model plug. Unit
			will not operate without correct model plug.
	High Pressure	31*	High ---pressure switch trip. Check refrigerant charge, outdoor fan operation
	Switch Open		and coils for airflow restrictions.
	Low Pressure
	Switch or Dis-	32*	Low---pressure switch or discharge temperature switch trip. Check refrigerant
	charge Temp		charge and indoor air flow.
	Switch Open
	Control Fault	45	Outdoor unit control board has failed. Control board needs to be replaced.
	Brown Out (230 v)	46	Line voltage < 187v for at least 4 seconds. Compressor and fan operation
			not allowed until voltage>190v. Verify line voltage.
			There is no 230v at the contactor when indoor unit is powered and cooling/
	No 230v at Unit	47	heating demand exists. Verify the disconnect is closed and 230v wiring is
			connected to the unit.
	Outdoor Air Temp	53	Outdoor air sensor not reading or out of range. Ohm out sensor and check
	Sensor Fault		wiring.
	Outdoor Coil	55	Coil sensor not reading or out of range. Ohm out sensor and check wiring.
	Sensor Fault
	Thermistors out of	56	Improper relationship between coil sensor and outdoor air sensor. Ohm out
	range		sensors and check wiring.
	Low Stage		Compressor operation detected then disappears while low stage demand
		71*	exists. Possible causes are internal compressor overload trip or start relay
	Thermal Cutout
			and capacitor held in circuit too long (if installed).
	High Stage		Compressor operation detected then disappears while high stage demand
		72*	exists. Possible causes are internal compressor overload trip or start relay
	Thermal Cutout
			and capacitor held in circuit too long (if installed).
	Contactor Shorted	73	Compressor voltage sensed when no demand for compressor operation
			exists. Contactor may be stuck closed or there is a wiring error.
	No 230V at	74	Compressor voltage not sensed when compressor should be starting. Con-
	Compressor		tactor may be stuck open or there is a wiring error.
	Low Stage	81	Thermal cutout occurs in three consecutive low/high stage cycles. Low
	Thermal Lockout		stage locked out for 4 hours or until 24v power recycled.
	High Stage	82	Thermal cutout occurs in three consecutive high/low stage cycles. High
	Thermal Lockout		stage locked out for 4 hours or until 24v power recycled.
	Low---Pressure	83	Low pressure switch trip has occurred during 3 consecutive cycles. Unit
	Lockout		operation locked out for 4 hours or until 24v power recycled.
	High ---Pressure	84	High pressure switch trip has occurred during 3 consecutive cycles. Unit
	Lockout		operation locked out for 4 hours or until 24v power recycled.

*Sequence: Compressor contactor is de--- energized and outdoor fan is energized for up to 15 minutes. If demand still exists, control will energize compressor contactor after 15 minute delay. If fault is cleared, unit will resume operation. If fault still exists, fan shuts off, and error code continues to flash. Control will attempt re--- start every 15 minutes. Cycling low voltage defeats the 15 minute delay.

25HPA6

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