Thermistor
Common temperature-sensing fault part. Confirm resistance range and connector.
Error Code: Hoshizaki Ice Machine E8
What it means: The E8 error code on Hoshizaki commercial ice machines indicates that the low-side pressure switch has opened — refrigerant pressure on the suction (low) side of the compressor has dropped below the switch’s minimum trip point. Hoshizaki installs this switch to protect the compressor from running in a state of refrigerant starvation, which causes overheating and accelerated wear.
E8 is a more serious fault than most maintenance-related errors because low suction pressure almost always points to a refrigerant leak or a blockage in the refrigerant circuit. Neither of these is a DIY repair. Commercial kitchen operators facing E8 should prioritize a service call — running the machine repeatedly against low suction pressure accelerates compressor wear and risks complete compressor failure.
Common Causes
- Low refrigerant charge (refrigerant leak) — The most common cause of E8. A slow leak over months or a sudden leak reduces the refrigerant charge below the level needed to maintain minimum suction pressure. The leak must be found and repaired before recharging.
- Blocked or restricted expansion valve (TXV/capillary tube) — A partially or fully blocked expansion device starves the evaporator of refrigerant, causing suction pressure to drop abnormally low even with a correct refrigerant charge.
- Iced-over evaporator — If the evaporator has accumulated excessive frost (from water distribution problems or abnormal operating conditions), it can block refrigerant flow, dropping suction pressure.
- Failed low-pressure switch — The switch itself has failed open, triggering E8 even when actual refrigerant pressure is within range.
- Dirty water filters or water distribution issues — On Hoshizaki cuber models, insufficient water flow to the evaporator during the freeze cycle can contribute to abnormal refrigerant circuit behavior.
Step-by-Step Diagnosis {#step-by-step-fix}
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Power down and let the machine fully defrost. Turn off the machine and disconnect power. Leave it off for at least 2 hours in a warm environment to ensure any accumulated frost on the evaporator has melted. Restart and monitor — if E8 returns during the first freeze cycle, the frost-over scenario is unlikely and a refrigerant issue is probable.
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Listen and observe. When the machine is running (if it will run briefly before faulting), listen to the compressor. A compressor starved of refrigerant often runs unusually quietly, with a lighter load sound than normal. You may also notice the evaporator plate is not freezing evenly across its surface.
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Inspect for visible refrigerant leaks. Examine all refrigerant line connections, the evaporator coil, condenser coil, and service valves for oily residue or visible discoloration. Refrigerant oil migrates with refrigerant and deposits at leak sites. This is a field check — not definitive, but useful.
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Test the low-pressure switch. With power off, locate the low-pressure switch (on the suction line, before the compressor). With pressure equalized in the system, the switch should be closed (continuity). If the switch reads open with pressure present and at rest, it has failed — replace it.
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Have a technician check refrigerant pressures. This is the definitive step. A technician connects a manifold gauge set to the service ports and reads actual operating suction and discharge pressures. Low suction pressure with correct ambient conditions confirms low refrigerant charge or a restriction.
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Leak search. If low charge is confirmed, a technician uses an electronic refrigerant leak detector or UV dye to locate the leak point. Common locations on Hoshizaki machines: evaporator inlet fitting, condenser coil joints, service valve Schrader cores.
How to Fix It
- Failed low-pressure switch: Replace with the correct Hoshizaki OEM switch. If the refrigerant circuit is under pressure when replacing, a technician must recover refrigerant first (if the switch is in a wet line).
- Low refrigerant (refrigerant leak): Locate and repair the leak, then evacuate and recharge to nameplate specification. This is a technician-only task requiring EPA 608 certification.
- Blocked expansion valve: Replace the TXV or clean the capillary tube (technician required — involves refrigerant recovery).
- Iced-over evaporator: Identify and correct the underlying water distribution or harvest issue, then allow a full defrost before restart.
Parts You May Need
- Hoshizaki Low Pressure Switch Replacement
- Hoshizaki Water Distribution Tube
- Hoshizaki Water Filter Replacement
- Refrigerant Leak Detector Electronic
- UV Dye for Refrigerant Leak Detection
When to Call a Technician
E8 almost always requires a certified commercial refrigeration technician. The only exception is a clearly failed low-pressure switch in a dry-circuit location (accessible without refrigerant recovery). If there is any chance of a refrigerant leak — which is the most likely cause — EPA 608 certification is required for diagnosis and repair. Do not attempt to add refrigerant without first fixing the leak — it is illegal to knowingly vent refrigerant, and an overcharge after leak repair will create additional problems. Prioritize a service call before the compressor sustains damage from continued low-refrigerant operation.
Related Error Codes
- Hoshizaki E7 Error Code — High-Side Pressure Switch Fault
- Hoshizaki E9 Error Code — Compressor Overload Fault
- Hoshizaki E2 Error Code — Freeze Cycle Overtime