Nor-Lake LogiTemp Walk-In Error Code CSA: Coil Sensor Shorted or Open
CSA means the evaporator coil temperature sensor on a Nor-Lake LogiTemp walk-in is shorted or open. Without it, defrost can end on time instead of on temperature, and the coil can build ice. Write the code down, keep door traffic low, do not chip at ice and call us if CSA stays on.
Medium: cooling continues at first, but icing builds without the coil sensor and can lead to a warming box.
- Code
- CSA
- Maker
- Nor-Lake
- Equipment
- Walk-in coolers & freezers
- Applies to
- LogiTemp / KE2 Evap OEM (Split-Pak systems, A1 refrigerants)
What does Nor-Lake error code CSA mean?
The coil sensor on a Nor-Lake Split-Pak walk-in tells the LogiTemp controller two things: when the coil is cold, and when a defrost has done its job. A normal defrost ends when this sensor shows that the coil is warm enough to be free of frost. If the sensor circuit shorts or opens, the controller cannot trust the number and shows CSA on the Basic Display. With the sensor missing, defrost can end on a timer instead of on temperature, which may stop it too early and leave frost on the fins, or let it run longer than needed. Ice then builds on the coil, airflow drops, and the box may slowly lose its cooling over hours or days rather than all at once. That slow drift is why CSA is easy to ignore on a day when the box still reads normal. The cause can be a coil sensor that has come loose from its clip, a damaged wire or connector, ice or water damage to the lead, or a failed sensor input on the controller.
Affected models and control systems
This applies to the LogiTemp controller on Nor-Lake walk-in coolers and freezers with a Split-Pak system. Other controller generations use different codes.
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
- CSA on the Basic Display
- Frost or ice building on the evaporator coil
- Box slowly warming over several hours
- Longer or more frequent defrost activity
Possible causes
Listed in Nor-Lake's documentation
- Coil temperature sensor that has come loose from its clip
- Damaged wire or connector on the coil sensor
- Ice or water that has damaged the coil sensor lead
- Failed coil sensor input on the LogiTemp controller
Other likely causes — what usually sits behind error code CSA on this control. A technician confirms which one it is before any part is replaced.
- Sensor lead frozen into a block of ice and cracked when a defrost freed it
- Sensor clip loosened by fan vibration so the probe sits in air instead of on the coil
- Repeated door openings in a freezer feeding heavy frost around the lead
Safe checks before calling for service
- Write down the code exactly as displayed.
- Look at the door and the strip curtain, and keep traffic through the walk-in low.
- Watch for ice building on the evaporator from outside the box, and do not chip at it.
- Call us to schedule service if CSA stays on.
How a technician diagnoses error code CSA
- Read CSA and check the defrost history if the controller shows it.
- Inspect the coil sensor position, clip and lead for ice and damage.
- Measure the sensor resistance against the coil temperature.
- Test the coil sensor input if the sensor is good.
- Clear the ice with a controlled defrost, then confirm defrost now ends on temperature.
- The sensor sits inside the evaporator housing next to fans and heaters that carry live voltage.
- Chipping ice off a coil can puncture the refrigerant tubing.
- Testing the sensor and input takes a meter and the sensor's temperature chart.
How error code CSA differs from similar codes
ASA concerns the return air sensor. CSA concerns the coil sensor, and its loss affects defrost more than the box temperature reading.
Technical reference
- Document
- LogiTemp Electronic Controller System Operations Manual (171527 Rev. A), Alarms & Notifications List pp. 47-51
- Edition
- 171527 Rev. A, 2025 (Refrigerated Solutions Group)
- Models / control
- LogiTemp / KE2 Evap OEM (Split-Pak systems, A1 refrigerants)
- Section
- Alarms & Notifications List, printed pp. 48-52; Troubleshooting Tables from p. 52
- 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 Nor-Lake walk-in cooler & freezer error codes
Can I keep using the box with CSA?
For a short time, with watching. Ice will keep growing, so call soon.
Should I scrape the ice?
No. A coil can be punctured easily and the repair would be much larger.
Will CSA clear by itself?
Only if a connection was briefly loose. If it returns, the sensor or lead needs testing.
Need help with Nor-Lake error code CSA?
A technician confirms the cause on site and gives you the price in writing before any work starts.