Nor-Lake Walk-In Error Code ASA: Return Air Sensor Shorted or Open
ASA is the Nor-Lake LogiTemp alarm for the return air temperature sensor reading shorted or open. That sensor tells the controller how warm the box is, so losing it removes the main temperature signal and the box may not hold its set temperature. Check the box with a thermometer, move food if it is warming, and call us.
High: the main temperature signal is lost and the box may not hold its set temperature, which puts food at risk.
- Code
- ASA
- 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 ASA mean?
The return air sensor sits where air comes back to the evaporator on a walk-in cooler or freezer cooled by a Split-Pak system with the KE2 Evap OEM controller. The controller reads it constantly and cuts the compressor in and out around the set point. If the sensor circuit shorts or opens, the number is no longer believable, and the controller flags ASA on the display. Because this is the main temperature signal, the effect is bigger than with the auxiliary sensor alarms: the compressor may run on a fallback, and the box may no longer hold its set temperature, running too warm or colder than intended. The alarm can be caused by a loose connector, a broken wire, moisture or ice that has shorted the sensor, or a failed return air input on the board. Frequent door openings and wet defrosts in a humid kitchen can make the moisture cause more likely, and the first practical step is simply to find out what the box is really doing with a thermometer.
Affected models and control systems
This applies to the LogiTemp / KE2 Evap OEM controller on Nor-Lake Split-Pak systems with A1 refrigerants, for walk-in coolers and freezers.
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
- ASA on the display with a yellow or red LED
- Box warmer or colder than the set point
- Compressor running far longer or shorter than usual
- Frost or water near the evaporator coil
Possible causes
Listed in Nor-Lake's documentation
- Loose connector on the return air sensor
- Broken wire between the return air sensor and the controller
- Moisture or ice that has shorted the sensor
- Failed return air input on the KE2 Evap OEM board
Other likely causes — what usually sits behind error code ASA on this control. A technician confirms which one it is before any part is replaced.
- Sensor body coated in ice after a long defrost problem, so it reads wrong
- Wire insulation cracked where it bends at the evaporator housing
- Condensate wicking into the connector in a humid kitchen
Safe checks before calling for service
- Read the code and note whether the LED is yellow or red.
- Put a thermometer inside the box and check it every hour or so.
- Move perishable food to another cooler if the box is warming.
- If ASA is still showing after the door has been closed for a while, call us to schedule service and give us your thermometer readings.
How a technician diagnoses error code ASA
- Read ASA and compare the box reading on the controller with a reference thermometer.
- Inspect the sensor, its connector and the wire for ice, moisture and damage.
- Measure the sensor resistance against its temperature.
- Test the return air input on the board if the sensor is good.
- Verify cooling returns after the repair and recheck the set point.
- The box may be warming, so food safety makes a quick, correct diagnosis important.
- The sensor sits inside the evaporator housing, near fans and live wiring.
- Deciding between sensor, wire and board needs resistance readings and a reference temperature.
How error code ASA differs from similar codes
A1A, A2A and A3A concern auxiliary inputs. ASA concerns the return air sensor, which the controller uses to run the box.
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 walk-in with ASA showing?
Only with close watching. Without the return air sensor the box may drift, so use a thermometer and be ready to move food.
Will ASA clear on its own?
Sometimes after a connector dries or reseats. A repeat means the sensor or its wire needs testing.
Does ASA mean the compressor is broken?
No. It reports a sensor reading, not the compressor.
Need help with Nor-Lake error code ASA?
A technician confirms the cause on site and gives you the price in writing before any work starts.