Kolpak Walk-In Cooler Error Code DOOR OPEN ALARM: Door Input Open
DOOR OPEN ALARM means a door input on the controller has stayed open while room temperature rose 5 F above its limit for the door alarm delay. Close the door fully and make sure nothing blocks it. Press ENTER to silence the alarm for one hour if it keeps sounding.
Medium: the room is warming while the door input is open, but cooling is not shut off by the alarm.
- Code
- DOOR OPEN ALARM
- Maker
- Kolpak
- Equipment
- Walk-in coolers & freezers
- Applies to
- ArcticFox OEM Controller with Deluxe Display (Kolpak walk-ins)
What does Kolpak DOOR OPEN ALARM mean?
The ArcticFox controller can be wired to a door switch. While that door input reads open, the controller also watches the room air temperature. The alarm needs both conditions together: the door input has to be open, and the room temperature has to be 5 F above ROOM TEMP plus AIR TEMP DIFF. That state must last for the time set in DOOR ALARM DELAY. Only then does DOOR OPEN ALARM appear as a text alarm in the Alarms menu. In plain terms, a door open briefly is ignored, and a door open while the room stays cold enough is also ignored. The alarm is aimed at a door left open long enough to let the room warm. The controller does not close the door or change cooling because of it. It only warns the operator, and the warning sounds again after the one-hour silence unless the condition is corrected.
Affected models and control systems
ArcticFox OEM Controller with Deluxe Display on Kolpak walk-ins. The manual lists DOOR OPEN ALARM in the Alarms menu on page 16 and does not limit it to a specific door or model.
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
- DOOR OPEN ALARM text in the Alarms menu
- Audible alarm from the display
- Room air feeling warmer than normal near the door
- Door not fully latched or held by a cart or pallet
Possible causes
Likely causes — what usually sits behind DOOR OPEN ALARM on this control. A technician confirms which one it is before any part is replaced.
- Door left ajar by a delivery cart, hand truck, or stacked product
- Worn door gasket or sagging hinges that stop the door latching fully
- Door switch or magnet out of alignment so the input reads open when the door is shut
- Door alarm delay set short for a room with frequent loading
Safe checks before calling for service
- Check that the door is closed and latched, and remove anything holding it open.
- Press ENTER to silence the alarm. It stays quiet for 1 hour and returns if the condition is not corrected.
- Look at the gasket along the door edge for gaps, and see whether the door swings shut on its own.
- Tell the technician whether the door really was open or was shut when the alarm sounded, since that points to the switch.
How a technician diagnoses DOOR OPEN ALARM
- Read the alarm and the settings for ROOM TEMP, AIR TEMP DIFF, and DOOR ALARM DELAY.
- Open and close the door while watching the door input state on the controller.
- Test the door switch and its wiring for continuity with a meter, with power off.
- Check hinges, latch and gasket for the cause of poor closing.
- Adjust the switch position or delay only after the door hardware is sound.
- Door switch wiring ties into the controller inputs, and testing it means working inside the control area.
- Changing delay and temperature settings on the controller needs the room's design values.
- Hinge and strike alignment on insulated walk-in doors is a repair that affects the room seal.
Technical reference
- Document
- ArcticFox Deluxe Display - Original Instructions, Installation, Operation and Maintenance Manual
- Edition
- Part No. 500002385-4, 5/23
- Models / control
- ArcticFox OEM Controller with Deluxe Display (Kolpak walk-ins)
- Section
- ArcticFox OEM Controller - Alarms Menu, p.16
- 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
Is the food spoiling while this alarm sounds?
Not by itself. The alarm warns that the door has been open while the room is warming. Closing the door usually stops the warming.
The door is closed and the alarm still shows. Why?
The door input may be reading open because the switch or magnet is out of line. That is a job for a technician.
Does silencing the alarm fix anything?
No. The manual says ENTER silences it for one hour, and it sounds again if the door condition is still present.
Need help with Kolpak DOOR OPEN ALARM?
A technician confirms the cause on site and gives you the price in writing before any work starts.