Nor-Lake LogiTemp Walk-In Error Code CHA: Humidity Board Link Lost

What does Nor-Lake error code CHA mean?

Some Nor-Lake walk-ins add a KE2 Humidity Control board that talks to the main LogiTemp controller. It is a separate piece, with its own power and its own link, and it carries the humidity part of the job. The main controller checks that link. If the humidity board stays silent for 10 seconds, the controller raises CHA. The control of humidity is no longer coordinated, and the display shows the alarm. The walk-in temperature control is not part of the humidity board, so cooling normally continues. What can change is the moisture level in the box, which may drift until communication returns, with effects on product that is sensitive to dryness or condensation. A drifting humidity level also matters for produce, meat and anything stored uncovered. The cause is most often in the link: the cable between the controller and the humidity board, power to the board, the connectors and terminals at each end, or the board itself. A power loss at the board looks the same as a cable problem.

Affected models and control systems

This applies to the LogiTemp / KE2 Evap OEM controller on Nor-Lake Split-Pak systems with A1 refrigerants that have a KE2 Humidity Control board.

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

• CHA on the display
• Humidity board display dark or frozen
• Box temperature normal
• Condensation or dry product that was not a problem before

Possible causes

Listed in Nor-Lake's documentation

• Cable between the controller and the humidity board
• Power to the humidity board
• Connectors and terminals at each end
• The humidity board itself

Other likely causes — what usually sits behind error code CHA on this control. A technician confirms which one it is before any part is replaced.

• Humidity board plug loosened after cleaning near the controller
• Condensation on terminals in a high-humidity kitchen
• Power adapter for the humidity board unplugged or failed

Safe checks before calling for service

How a technician diagnoses error code CHA

1. Read CHA and see whether the humidity board has power and a display.
2. Confirm the box temperature is under control.
3. Inspect the cable and terminals at both ends.
4. Check the board address and communication settings.
5. Replace the cable or board only after the link test.

How error code CHA differs from similar codes

CHA concerns the humidity board only, so compressor and temperature alarms such as CCA or ASA point to different parts.

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.