Hoshizaki Refrigerator Error Code Lo: Low Temperature Alarm
Lo on a Hoshizaki Steelheart A-Series appliance means the refrigerator cabinet has been below 26F (-3.3C), or the freezer below -23F (-30.6C), for more than 2 hours. It resets automatically. If obvious corrections do not bring the temperature back, call a qualified service technician.
Medium: the cabinet is too cold and may be freezing product, but the cause is often a setting.
- Code
- Lo
- Maker
- Hoshizaki
- Equipment
- Reach-in refrigerators
- Applies to
- Steelheart A-Series upright controller
What does Hoshizaki error code Lo mean?
Lo is the cold-side counterpart of Hi. The controller waits until the cabinet has been below its limit for more than 2 hours before it raises the alarm. The limits are 26F (-3.3C) for a refrigerator and -23F (-30.6C) for a freezer. A refrigerator below 26F is cold enough to freeze produce and drinks, and a freezer far below its range wastes energy. The alarm clears itself when the temperature returns to its range. The manual suggests obvious corrections first, which generally means checking the temperature setting and anything that might leave the cabinet over-cooled, such as blocked airflow or product stored against the evaporator. If those do not help, the manual says to call a qualified service technician. The cause may be a sensor reading wrong or a control that keeps the compressor running.
Affected models and control systems
Steelheart Upright A-Series: R1A and R2A refrigerators and F1A and F2A freezers, with the DT2A also named in the manual.
Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.
What you may notice
- Lo on the control display
- Frozen produce or drinks in the refrigerator
- Frost buildup on shelves or walls
- Compressor running without rest
Possible causes
Likely causes — what usually sits behind error code Lo on this control. A technician confirms which one it is before any part is replaced.
- A temperature setting that was changed by mistake
- Product stacked tight against the evaporator, causing a local freeze
- A cabinet thermistor that reads warm, so the compressor never stops
Safe checks before calling for service
- Check the temperature setting and set it to the normal range.
- Move product away from the back wall and the evaporator area.
- Watch a separate thermometer in the cabinet.
- Note the setting you found and how long Lo showed.
How a technician diagnoses error code Lo
- Compare the cabinet reading with a calibrated thermometer.
- Check the set point and any recent changes.
- Check airflow around the evaporator and shelf loading.
- Test the cabinet thermistor and the compressor control output.
- Replace the sensor or control only after the test shows which is wrong.
- Whether the compressor is being held on needs measurements on live control wiring.
- A false sensor reading looks the same as a real overcooled cabinet from the outside.
- Opening the control area exposes line voltage.
How error code Lo differs from similar codes
Lo is the cold-side alarm; Hi is the warm-side alarm, with different limits for refrigerators and freezers.
Technical reference
- Maker documentation
- Hoshizaki owner support
- Edition
- Number 73237, issued 2-25-2019, revised 3-24-2022
- Models / control
- Steelheart A-Series upright controller
- Section
- Alarm Safeties, Alarm Signals table, pp. 30-31
- Checked
- October 2026
We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.
Related Hoshizaki reach-in refrigerator error codes
Do I need to reset Lo?
No. It resets automatically once the temperature returns to normal.
What are the limits?
Below 26F (-3.3C) for the refrigerator and below -23F (-30.6C) for the freezer, for more than 2 hours.
Could it be my setting?
Yes, check it first. The manual refers to obvious corrections before a service call.
Need help with Hoshizaki error code Lo?
A technician confirms the cause on site and gives you the price in writing before any work starts.