Sanyo CHDXR09663, CHDX09663, CHDX07263, CHDXR07263* service manual F16 Alarm Alarm code

4. W-2WAY ECO-i Alarm Codes

W-2WAY ECO-i SYSTEM Trouble Diagnosis

F16 Alarm

Alarm code	F16
Alarm meaning	High-pressure sensor trouble (abnormal rise in high pressure) (In some cases this may not be
	the result of a high-pressure sensor malfunction.)
Alarm conditions	• High-pressure SW activated although the detected pressure was lower (439.4 psi or below)
	than the high-pressure SW activation pressure: Undershift

•High-pressure SW failed to activate although the detected pressure was higher (497.5 psi or above) than the high-pressure SW activation pressure: Overshift

•The saturation temperature at the detected pressure is 10°F or more below the highest indoor- unit E1 temperature continuously for 30 minutes.

•High-pressure sensor disconnected or open circuit.

Probable cause	(1)	High-pressure sensor malfunction
	(2)	Failure to connect the connector to the outdoor unit PCB
	(3)	Failure to open the service valve
	(4)	Clogged tubing
	(5) Valve leakage
	(6)	Over-charging
	(7)	Outdoor unit PCB failure
	(8)	Electrical noise
Check	(1)	High-pressure sensor failure
		• Check the sensor resistance value. (Use a tester and measure the resistance between
		sensor No. 1 and No. 3)
		Resistance of less than 10kΩ indicates a short circuit or other trouble.
		Resistance of 10kΩ - 200kΩ is normal. Resistance of more than 200kΩ indicates
		an open circuit or other trouble.
		• Connect a gauge to the high-pressure outlet and check for changes in the value
		dispalyed by the monitoring software, and for large deviation of the gauge pressure.
		• During heating, check whether the temperature is lower than the highest indoor-unit E1
		temperature.
		* The pressure detected by the high-pressure sensor is the highest pressure in the system.
		Therefore during heating the converted saturation temperature will never be lower than
		any indoor-unit E1 temperature. During cooling this temperature will never be lower
		than the outdoor unit liquid temperature.
	(2)	Failure to open the service valve, clogged tubing, valve leakage, over-charging.
		In all of these cases an alarm occurs when there are rapid pressure fluctuations and tracking
		of the detected pressure is poor.
		• Check the open/closed status of the valve.
		• Check for clogging of the tubing.
		To check for clogging, disconnect the high-pressure sensor from the PCB and check
		whether the high-pressure SW activates.
		• Check for valve leakage and over-charging
		When valve leakage or over-charging occurs, refrigerant is likely to accumulate in the
		outdoor units or indoor units, resulting in a sudden rise in pressure at start that occurs
		before the refrigerant in the heat exchanger is discharged.
		* The representative valves to check are the liquid valves and mechanical valves.
	(3)	Outdoor unit PCB failure
		• The check items are the same as for a high-pressure sensor malfunction.
		A normal PCB is needed to determine whether the problem is a PCB failure or a pressure
		sensor malfunction. If an abnormality was found at the check items for a high-pressure
		sensor malfunction, first try replacing the PCB and check again.
		Trouble is corrected: Outdoor unit PCB failure
		Trouble is not corrected: High-pressure sensor malfunction
		Continued

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