Nor-Lake LogiTemp Walk-In Error Code A2A: AUX2 Sensor Shorted or Open
A2A means the AUX2 temperature sensor on a Nor-Lake LogiTemp controller is shorted or open. The main box sensors are separate, so the walk-in may keep cooling while the alarm shows. Write down the code and LED color, confirm the box temperature yourself and call us if it stays.
Medium: an auxiliary reading is lost, but the walk-in may keep cooling.
- Code
- A2A
- 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 A2A mean?
AUX2 is a spare sensor input on the KE2 Evap OEM board used on Nor-Lake Split-Pak walk-in coolers and freezers. It can watch an extra point in the system, and the controller raises A2A when that input stops giving a usable reading. A sensor wire that touches ground or itself makes the input read as shorted, and a wire that has broken or come out of its plug makes it read as open. Either way the controller cannot trust the number and flags it. Because the main box sensors work on separate inputs, the walk-in may keep cooling normally. What changes is only the function tied to AUX2, which could be an extra probe or a monitored point chosen at installation. The controller keeps polling, so the alarm goes away when a believable reading returns, and an intermittent connection can make it appear and vanish. A lead that is pinched near the evaporator or the condensing section is a common place for that to start.
Affected models and control systems
This applies to the LogiTemp / KE2 Evap OEM board 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
- A2A shown with an alarm LED on the controller
- Walk-in temperature normal on your own thermometer
- The extra monitored point no longer reads
- The alarm drops out and returns by itself
Possible causes
Listed in Nor-Lake's documentation
- The sensor connected to the AUX2 input
- The wire and plug between that sensor and the board
- The AUX2 input on the controller
- A lead pinched near the evaporator or condensing section
Other likely causes — what usually sits behind error code A2A on this control. A technician confirms which one it is before any part is replaced.
- Sensor wire chafed by a fan guard or vibrating against sharp metal
- Plug partly pulled out after a past service visit
- Condensate that froze inside the sensor connector
Safe checks before calling for service
- Write down A2A and the LED color.
- Confirm the box temperature with your own thermometer.
- Keep the door closed and check that the gasket is sealing all the way around.
- If the code is still on after some time, call us to schedule service and tell us when it began.
How a technician diagnoses error code A2A
- Read A2A and identify what AUX2 monitors on this installation.
- Check the sensor reading against a reference thermometer at the same point.
- Inspect the lead from the sensor to the board, including near the evaporator and condensing section.
- Measure sensor resistance, then test the AUX2 input.
- Replace the failed sensor or wire only after the result.
- The board and its inputs sit in a control area with live voltage.
- A pinched lead inside the evaporator or condensing section takes dismantling guards around fans.
- Sensor and input tests need a meter and the sensor's temperature chart.
How error code A2A differs from similar codes
A1A and A3A are the same alarm for AUX1 and AUX3, so A2A should not be treated as the main box sensor alarm.
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
Does A2A mean my cooler is warming?
Not by itself. The main box sensors are on other inputs, but check with a thermometer to be sure.
Will it clear on its own?
It may if a connection was briefly loose. If it keeps coming back, the sensor or lead needs testing.
Can I silence the alarm?
Please do not change controller settings. We can find which sensor is behind A2A and fix it.
Need help with Nor-Lake error code A2A?
A technician confirms the cause on site and gives you the price in writing before any work starts.