Polar King Walk-In Cooler Alarm LOW AIR TEMP: Room Too Cold
LOW AIR TEMP is an alarm on the KE2 evaporator control: the room temperature has stayed below a limit for longer than the alarm delay. The document gives no repair steps. Check the box with a thermometer, since a freezing cooler can damage produce and drinks.
Medium: stored product can freeze, though the cooler is not warm.
- Code
- LOW AIR TEMP
- Maker
- Polar King
- Equipment
- Walk-in coolers & freezers
- Applies to
- Polar King walk-in coolers/freezers with KE2 Evaporator Efficiency Evap OEM board (Basic Display / Combo Display)
What does Polar King LOW AIR TEMP mean?
The low side of the timed room check works from a simpler threshold. The KE2 Evaporator Efficiency board takes ROOM TEMP and subtracts the LOW TEMP ALARM OFFSET. When the room temperature stays below that value for longer than the LOW TEMP ALARM DELAY, the Alarms Status Menu lists LOW AIR TEMP. On the Combo Display the name appears; on the Basic Display only a red or yellow light does. The installation instructions give the trigger and mention the CLEAR ALARMS menu item, nothing else. They give no cause and no steps. A walk-in cooler that is colder than intended is less urgent for food safety than a warm one, but produce, dairy and drinks can freeze, and a cooler that keeps running too cold also wastes energy. The alarm does not explain why the cold has built up.
Affected models and control systems
Polar King walk-in coolers and freezers fitted with the KE2 Evaporator Efficiency Evap OEM board, with either the Basic Display or the Combo Display. The alarm is listed in the Alarms Status Menu, which is view only, on page 14 of the KE2 installation instructions.
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
- Red or yellow light on the Basic Display
- LOW AIR TEMP on the Combo Display
- Ice crystals on produce or frozen drink bottles
Possible causes
Likely causes — what usually sits behind LOW AIR TEMP on this control. A technician confirms which one it is before any part is replaced.
- A room temperature setpoint entered lower than intended
- A room sensor reading higher than the real air so the box keeps cooling
- A compressor that runs on after the box is cold
- A defrost that is not completing so the box is overcooled by a frosted coil
Safe checks before calling for service
- Check the temperature in several places in the box with a thermometer.
- Look for frozen items near the evaporator fans and move them away.
- Check what the room temperature setting is on the display, without changing parameters you do not know.
- Clear the alarm with CLEAR ALARMS. If LOW AIR TEMP returns, note the thermometer readings and arrange service.
How a technician diagnoses LOW AIR TEMP
- Read the alarm, the room temperature and the offset and delay settings.
- Compare the room sensor with a reference thermometer.
- Check that the compressor cycles off at the setpoint.
- Check defrost operation and the coil for ice.
- Correct the setpoint, the sensor or the control as the tests show.
- Compressor and control relay checks involve live 208-240 V wiring. Alarm offsets and delays are control parameters that should be changed with the box's settings in hand. A cold box may also come from a refrigerant circuit problem that needs gauges.
How LOW AIR TEMP differs from similar codes
LOW AIR TEMP is the cold counterpart of HIGH AIR TEMP. It uses a LOW TEMP ALARM OFFSET subtracted from ROOM TEMP rather than the air temperature difference setting.
Technical reference
- Document
- KE2 Evaporator Efficiency Installation Instructions N.1.1 (posted on polarking.com Downloads as ke2-installation.pdf; authored by KE2 Therm Solutions)
- Edition
- N.1.1 July 2015
- Models / control
- Polar King walk-in coolers/freezers with KE2 Evaporator Efficiency Evap OEM board (Basic Display / Combo Display)
- Section
- Alarms Status Menu (view only), p. 14 (Alarm Status Menu listed p. 13)
- 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 Polar King walk-in cooler & freezer error codes
Can LOW AIR TEMP spoil food?
Yes, produce, dairy and drinks can freeze. Check what is near the evaporator.
Is a cold box an emergency?
Less than a warm one, but it should be corrected soon.
Does the alarm mean the sensor failed?
No. A failed sensor appears as T2 AIR SENSOR. This alarm means the room reading itself stayed low.
Need help with Polar King LOW AIR TEMP?
A technician confirms the cause on site and gives you the price in writing before any work starts.