C. defrost alarm (e3), D. high pressure alarm (e4), C. defrost alarm (e3) d. high pressure alarm (e4) – Hoshizaki HUR40A(-D) User Manual
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c. Defrost Alarm (E3)
If the defrost thermistor does not turn off in one hour after defrost begins, "E3" is 
displayed. When "E3" is displayed, the next step in the defrost termination process 
(drain - fan delay - defrost display delay) begins.
Reset Options
To reset the alarm, turn the unit off and then back on.
Possible Causes
•	Trouble	with	the	defrost	heater.
•	The	temperature	fuse	is	blown.
•	Trouble	with	the	defrost	thermistor	(orange).
d. High Pressure Alarm (E4)
In order to protect the compressor if the discharge pressure reaches a preset value 
(outside the normal operating range), a switch will temporarily stop the compressor. 
At another preset pressure, the compressor will attempt to restart. If the switch is 
triggered 5 or more times in one hour, "E4" will be displayed.
Reset Options
To reset the alarm, turn the unit off and then back on.
Possible Causes
•	The	condenser	air	filter	is	dirty.
•	There	is	blockage	or	contamination	inside	the	capillary	tube	or	elsewhere	in	the	
refrigeration circuit.
• The condenser fan motor is locked or otherwise not functioning.