Kolpak Walk-In Cooler Error Code MONITOR TEMP3 SENSOR ALARM: Temp 3 Open or Shorted
MONITOR TEMP3 SENSOR ALARM means the Temp 3 input is shorted or open. The stand-alone Display cannot read the sensor used as Monitor 3. Check the Alarms & Variables menu for active alarms and have the sensor circuit tested.
Low: one monitor reading is lost, and the manual does not say cooling stops.
- Code
- MONITOR TEMP3 SENSOR ALARM
- Maker
- Kolpak
- Equipment
- Walk-in coolers & freezers
- Applies to
- ArcticFox Deluxe Display, stand-alone
What does Kolpak MONITOR TEMP3 SENSOR ALARM mean?
Temp 3 is the third temperature input on the stand-alone Deluxe Display, and it can serve as a monitor sensor for a spot other than the room control point. The Display checks that circuit continuously. A short, with almost no resistance, or an open, with none connected, cannot come from a working sensor. When either is seen, the Display shows the text alarm MONITOR TEMP3 SENSOR ALARM in the Alarms & Variables menu. The manual lists exactly that meaning, Temp 3 input shorted or open, and no causes. The alarm is about the sensor circuit rather than the temperature of what it monitors. Monitor high and low alarms for Temp 3 need a valid reading, so they cannot act while this alarm is active. The manual mentions a DISP CLEAR ALARM variable to clear alarms set in the Display.
Affected models and control systems
ArcticFox Deluxe Display, stand-alone, on Kolpak walk-ins. The manual lists this alarm in the Alarms & Variables menu on page 9 of the stand-alone section.
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
- MONITOR TEMP3 SENSOR ALARM in the Alarms & Variables menu
- Alarm indication on the Display
- No Temp 3 monitor value
- Monitor 3 high and low alarms not acting
Possible causes
Likely causes — what usually sits behind MONITOR TEMP3 SENSOR ALARM on this control. A technician confirms which one it is before any part is replaced.
- Temp 3 monitor sensor unplugged or its lead broken
- Lead pinched by a door, hinge or shelf
- Corroded connector from damp conditions
- Temp 3 assigned as a monitor input with no sensor installed
Safe checks before calling for service
- Scroll the Alarms & Variables menu to see active alarms.
- Check the monitored spot with a thermometer.
- Look at the visible lead for a break or crush, without pulling or cutting it.
- Give the technician the alarm names and your thermometer reading.
How a technician diagnoses MONITOR TEMP3 SENSOR ALARM
- Read the active alarms and confirm Temp 3 is a monitor input.
- Inspect the sensor and lead.
- Measure resistance against the chart, and test continuity and isolation of the lead.
- Repair or replace.
- Clear the alarm and confirm it stays clear.
- Leads end inside the powered Display housing.
- Telling an open lead from a shorted sensor takes a meter and a chart.
- Clearing the alarm before repair hides the problem.
Technical reference
- Document
- ArcticFox Deluxe Display - Original Instructions, Installation, Operation and Maintenance Manual
- Edition
- Part No. 500002385-4, 5/23
- Models / control
- ArcticFox Deluxe Display, stand-alone
- Section
- Deluxe Display - Stand Alone - Alarms & Variables Menu, p.9
- 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 Kolpak walk-in cooler & freezer error codes
Does this mean Monitor 3 is too warm?
No. It means the sensor circuit is shorted or open, so there is no reading.
How is it different from ROOMTEMP3 SENSOR ALARM?
The electrical condition is the same. The name shows whether Temp 3 is used as a room or a monitor input.
Are the high and low Temp 3 alarms still active?
They need a valid reading and cannot act while the sensor circuit is shorted or open.
Need help with Kolpak MONITOR TEMP3 SENSOR ALARM?
A technician confirms the cause on site and gives you the price in writing before any work starts.