Bally Walk-In Cooler Error Code LSH: Low Superheat Alarm
LSH, Low Superheat Alarm, on a Bally walk-in evaporator with the SmartVap+ controller means superheat is below the lower limit. The manual lists the trigger and no repair steps. Check the suction line for frost and call a technician.
Medium: the controller sees too little superheat, which can stress the compressor if it continues.
- Code
- LSH
- Maker
- Bally
- Equipment
- Walk-in coolers & freezers
- Applies to
- SmartVap+ evaporator controller (on-board display / dashboard display), used with Bally walk-in evaporators
What does Bally error code LSH mean?
Superheat is the margin by which refrigerant vapor leaving the coil is warmer than its boiling point at the measured suction pressure. SmartVap+ calculates it from its suction pressure and suction temperature readings and keeps it between a lower and an upper limit. A low value means the coil is being fed more liquid than it can evaporate, which leaves too little margin before liquid could travel on toward the compressor. When the calculated value falls below the lower limit, the controller raises the Low Superheat Alarm and shows LSH. The manual's Alarm Status Menu gives only that trigger, superheat below the lower limit, with no causes or steps. HSH is the mirror alarm for superheat that is too high. The manual does not say how the controller changes its feed while LSH is active.
Affected models and control systems
The SmartVap+ evaporator controller, with its on-board display or dashboard display, used with Bally walk-in evaporators. The manual is Bulletin B30-SVP-OM-2.05 for firmware 2.05 and later.
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
- LSH shows in the active alarm list
- Frost or sweating appears on the suction line back toward the compressor
- The coil looks wet or heavily iced
Possible causes
Listed in Bally's documentation
- Superheat below the lower limit
Other likely causes — what usually sits behind error code LSH on this control. A technician confirms which one it is before any part is replaced.
- Metering valve stuck open or hunting, feeding too much refrigerant
- Suction temperature sensor loose on the line and reading too cold
- Fan or airflow reduced across the coil, so less heat reaches the refrigerant
- Suction pressure sensor reading higher than actual
Safe checks before calling for service
- Scroll active alarms and note the light color and any SSA or PSA entries.
- Look at the suction line and coil, without opening panels, for frost or sweating that is heavier than usual.
- Check that the evaporator fans are turning and nothing blocks the airflow, such as product stacked against the coil.
- Tell the technician what you saw on the line and the room temperature.
How a technician diagnoses error code LSH
- Read active alarms and compare the controller's superheat with measured values.
- Verify the pressure and temperature sensors with gauges and a clamp thermometer.
- Check the metering valve movement and the liquid line for overfeeding.
- Check evaporator fan operation and coil airflow.
- Correct the confirmed cause, clear alarms, and watch superheat stabilize above the limit.
- Checking superheat means gauges on the refrigerant circuit and certified refrigerant handling.
- Liquid reaching the compressor can damage it, so diagnosis should not be a guess by trial and error.
How error code LSH differs from similar codes
LSH is low superheat and HSH is high superheat. Sensor alarms such as SSA and PSA can make either value unreliable.
Technical reference
- Document
- SmartVap+ Intuitive Evaporator Control Technology, Operating Instructions (Bulletin B30-SVP-OM-2.05, Part # 1107523)
- Edition
- B30-SVP-OM-2.05, firmware 2.05+, dated 17/09/21
- Models / control
- SmartVap+ evaporator controller (on-board display / dashboard display), used with Bally walk-in evaporators
- Section
- Alarm Status Menu, page 6 of the PDF
- 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 Bally walk-in cooler & freezer error codes
Is LSH dangerous for the compressor?
The manual does not say. Low superheat means little margin before liquid could return, so we would have it checked soon.
Can ice on the coil cause LSH?
Heavy ice reduces airflow and heat to the refrigerant, which can lower superheat. It is one thing a technician looks at.
How is LSH different from LPA?
LSH is about superheat. LPA is a count of low suction pressure events.
Need help with Bally error code LSH?
A technician confirms the cause on site and gives you the price in writing before any work starts.