Nor-Lake LogiTemp Walk-In Error Code CLL: Lead/Lag Communication Lost

What does Nor-Lake error code CLL mean?

Systems with more than one compressor or evaporator use a lead and lag arrangement. One controller leads, the others follow, and they share the work and take turns so no single unit wears faster. That only works while the controllers can talk. The LogiTemp controller watches the link, and when the communication between lead and lag drops, it shows CLL. The controllers can no longer rotate or stage properly, so the walk-in may keep cooling on one unit while the others run without coordination, with uneven wear and sometimes uneven temperatures in a large box. Check which controller displays the code, because the display tells a technician which side noticed the loss. The usual causes are the communication cable between the controllers, the connectors and terminals on each controller, power to the lag controller, or the lead and lag settings. A lag controller that lost power looks the same on the lead controller as a cut cable.

Affected models and control systems

This applies to the LogiTemp / KE2 Evap OEM controllers on Nor-Lake Split-Pak systems with A1 refrigerants that are set up as lead and lag.

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

• CLL on one or both controller displays
• One evaporator or compressor running alone
• Uneven temperature across a large box
• A lag controller display that is dark

Possible causes

Listed in Nor-Lake's documentation

• Communication cable between lead and lag controllers
• Connectors and terminals on each controller
• Power to the lag controller
• Lead and lag settings

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

• Cable cut or crimped by a shelf or ceiling panel during box changes
• Lag controller breaker tripped separately from the lead
• Controller replaced earlier and left with a duplicate lead address

Safe checks before calling for service

How a technician diagnoses error code CLL

1. Read CLL on both controllers and see which are powered.
2. Check the box temperature and which units are running.
3. Inspect the communication cable run and terminals.
4. Verify the lead and lag settings and addresses on each controller.
5. Replace the cable or a controller only after the link test.

How error code CLL differs from similar codes

CoA is the similar alarm for bonded controllers after one minute, while CLL is specific to lead and lag units.

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.