Nor-Lake LogiTemp Walk-In Error Code SSA: Suction Temperature Sensor
SSA says the suction temperature sensor is shorted or open on a Nor-Lake walk-in whose Split-Pak system runs the LogiTemp controller with the KE2 Evap OEM board. A bad reading makes the valve control unreliable. Note the code and LED color, check the box with a thermometer and keep the door shut and latched.
Medium: valve control is less accurate and the box may drift warm, but the system usually keeps running.
- Code
- SSA
- 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 SSA mean?
The suction temperature sensor measures how warm the gas is as it leaves the evaporator. The KE2 Evap OEM controller uses that reading with suction pressure to work out superheat, which it needs to meter refrigerant into the coil. When the sensor circuit is shorted or open, the number is not believable, and the Basic Display shows SSA. A bad reading makes the valve control unreliable, so staff see the code and the box can drift warm or the compressor may behave oddly until the reading returns. Most alarms clear once the condition ends, so a connector that was only briefly loose can clear it without service. The suction line is cold and often wet, so the sensor lives in a hard place. Causes include a loose connector at the LogiTemp board, a sensor lead chafed where it runs along the suction line, a failed input on the board, or wiring left loose after earlier service work on the Split-Pak.
Affected models and control systems
This applies to the LogiTemp / KE2 Evap OEM controller on Nor-Lake Split-Pak walk-in coolers and freezers with A1 refrigerants.
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
- SSA on the Basic Display
- Box drifting warm
- Compressor cycling or running oddly
- Frost pattern on the suction line looking unusual
Possible causes
Listed in Nor-Lake's documentation
- Loose connector on the suction temperature sensor at the board
- Sensor lead chafed where it runs along the suction line
- Failed SSA input on the KE2 Evap OEM controller
- Wiring left loose after earlier service work
Other likely causes — what usually sits behind error code SSA on this control. A technician confirms which one it is before any part is replaced.
- Sensor clamp loosened so the probe reads air instead of the line
- Insulation wrap missing, letting ambient heat skew the reading
- Sensor lead brittle from cold and cracked at a bend
Safe checks before calling for service
- Note the code and the LED color showing.
- Check the walk-in with a thermometer and keep the door shut.
- Make sure the door is fully latched and the strip curtain, if you have one, is hanging straight.
- Most alarms clear once the condition ends. If SSA remains, call us to schedule service.
How a technician diagnoses error code SSA
- Read SSA and the suction temperature shown.
- Compare with a reference probe on the suction line.
- Inspect the sensor mounting, insulation, lead and connector.
- Measure the sensor resistance and test the board input.
- Replace the sensor or lead only after the result.
- The sensor is on the suction line near moving parts and live wiring.
- Superheat has to be checked together with pressure, which needs gauges.
- Sensor position and insulation affect the reading and must be restored correctly.
How error code SSA differs from similar codes
PSA is the pressure sensor partner of this reading. ASA concerns the return air sensor, a different job.
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
Will SSA clear itself?
Often when a connector was only briefly loose. A repeat means testing.
Does SSA stop cooling?
Not always, but the valve control can be off, so the box may drift warm.
Is SSA the same as PSA?
No. SSA is temperature, PSA is pressure, and they are on different sensors.
Need help with Nor-Lake error code SSA?
A technician confirms the cause on site and gives you the price in writing before any work starts.