Defrost Alarm (E3); High Pressure Alarm (E4) - Hoshizaki HUR40A(-D) Service Manual

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.
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