Kolpak Walk-In Cooler Error Code PUMPDOWN TIMEOUT: LPCO Pump Down Too Long
PUMPDOWN TIMEOUT means the maximum time for the LPCO pump down was exceeded. In pump down, the compressor runs until suction pressure drops to its cutout, and here it took too long. Press ENTER to silence it for one hour and have a technician check the refrigeration circuit.
High: the refrigeration circuit is not completing pump down, which can affect compressor life and room temperature.
- Code
- PUMPDOWN TIMEOUT
- Maker
- Kolpak
- Equipment
- Walk-in coolers & freezers
- Applies to
- ArcticFox OEM Controller with Deluxe Display (Kolpak walk-ins)
What does Kolpak PUMPDOWN TIMEOUT mean?
Many walk-in systems use pump down: when the room is satisfied, the liquid line shuts and the compressor keeps running briefly to pull refrigerant out of the evaporator until suction pressure falls to the low-pressure cutout, abbreviated LPCO in the manual. The controller allows a maximum time for this to finish. When the pump down takes longer than that maximum, the pressure never reached the cutout in time, and the controller posts the text alarm PUMPDOWN TIMEOUT in the Alarms menu. The manual gives only the time limit and no causes. The alarm is a refrigeration alarm rather than a control or sensor alarm, because it describes how the pressure behaved. It can mean refrigerant is leaking back, a valve is not seating, or a pressure setting is wrong, but the manual does not say, so only gauges can settle it. It sounds again after the one-hour silence if the condition continues.
Affected models and control systems
ArcticFox OEM Controller with Deluxe Display on Kolpak walk-in systems that use LPCO pump down. The manual lists this alarm in the Alarms menu on page 16.
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
- PUMPDOWN TIMEOUT text in the Alarms menu
- Audible alarm from the display
- Compressor running longer than usual after the room stops calling for cooling
- Alarm returning after being silenced
Possible causes
Likely causes — what usually sits behind PUMPDOWN TIMEOUT on this control. A technician confirms which one it is before any part is replaced.
- Liquid line solenoid valve leaking through, so refrigerant keeps feeding the evaporator during pump down
- Compressor valves worn, so it cannot pull suction pressure down to the cutout
- Low-pressure cutout set too low for the system to reach
- Pressure transducer or switch reading incorrectly
Safe checks before calling for service
- Press ENTER to silence the alarm. It stays quiet for 1 hour and sounds again if the condition remains.
- Listen from outside the room to the condensing unit and note if it runs for long stretches after the room is cold.
- Check that the room is holding temperature and note if it is warmer than usual.
- Do not touch the condensing unit or any valves. Write down the alarm text, the time, and how the unit has been behaving for the technician.
How a technician diagnoses PUMPDOWN TIMEOUT
- Read the alarm, the pump down time limit, and the LPCO setting from the controller.
- Connect gauges and watch suction pressure through a complete pump down.
- Check the liquid line solenoid for a valve that is not closing fully.
- Test the compressor's pumping ability and check the cutout switch or transducer against the gauges.
- Correct the leaking valve, pressure device, or setting, then confirm pump down finishes within the time limit.
- Pump down diagnosis needs gauges on the refrigerant circuit, which only a licensed technician may connect.
- Solenoid valves and compressor terminals involve high-voltage wiring.
- Adjusting pressure setpoints without measurements can damage the compressor.
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 PUMPDOWN TIMEOUT dangerous?
The manual does not describe a danger. It does mean the refrigeration circuit is not behaving as designed, so schedule a technician.
Does LPCO mean the same as low pressure?
LPCO is the cutout point for suction pressure during pump down. The separate LOW PRESSURE alarm covers low suction pressure too many times.
Will it stop on its own?
Silencing lasts one hour. The cause is in the refrigeration circuit, so expect the alarm to return until it is repaired.
Need help with Kolpak PUMPDOWN TIMEOUT?
A technician confirms the cause on site and gives you the price in writing before any work starts.