Kold-Draft Ice Machine Error Code 50: Harvest Cycle Too Long
Code 50 means the harvest cycle exceeded 20 minutes and the control shut down the ice maker. It exists only on K4B boards Rev 1.1 to 1.5, so check the board revision. A technician should check the evaporator probe, actuator motor, switches and hot gas valve.
High: the control shuts down the ice maker when harvest runs over 20 minutes.
- Code
- 50 (harvest cycle too long, LED 50)
- Maker
- Kold-Draft
- Equipment
- Ice machines
- Applies to
- Kold-Draft 60 Series electronic controller (K4B boards, revisions 1.1 to 1.80)
What does Kold-Draft error code 50 mean?
Harvest is the short step when the evaporator warms enough to release the ice and the water plate lowers to let it drop. If harvest drags on, something is not finishing, and the K4B controller stops the machine after 20 minutes with Code 50: 50 (harvest cycle too long, LED 50). The manual lists six causes. The evaporator probe may be out of adjustment or open, so the control never sees the temperature it wants. The actuator motor may not raise or lower the water plate. The controller may be defective. The arms-down switch may be stuck open or closed. The hot gas valve may not open, so the evaporator does not warm. Or a contactor may be bad. Reset the controller to clear the code. Boards Rev 1.6 and higher no longer have Code 50; they use a five-minute maximum defrost instead.
Affected models and control systems
Kold-Draft GT36x, GT56x, GB56x and GB106x machines with a K4B board of Rev 1.1 to 1.5 only; Rev 1.6 and higher swap Code 50 for a 5-minute maximum defrost.
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
- LED 50 lit on the controller
- Ice stuck on the evaporator
- Machine stopped partway through harvest
Possible causes
Listed in Kold-Draft's documentation
- Evaporator probe out of adjustment or open
- Actuator motor will not raise or lower the water plate
- Controller defective
- Arms-down switch stuck open or closed
- Hot gas valve will not open
- Bad contactor
Other likely causes — what usually sits behind error code 50 on this control. A technician confirms which one it is before any part is replaced.
- Ice frozen solid on the evaporator from an earlier over-freeze, so harvest cannot finish
- A hot gas valve coil that has lost power
Safe checks before calling for service
- Check the board revision printed on the controller.
- Look for ice stuck on the evaporator through the access panel, without chipping at it.
- Reset the controller and watch whether the plate lowers.
- If Code 50 returns, tell the technician whether the plate moved and the board revision.
How a technician diagnoses error code 50
- Read the code and confirm Rev 1.1 to 1.5.
- Check the evaporator probe adjustment and continuity.
- Test the actuator motor and the arms-down switch.
- Check that the hot gas valve opens and the contactor pulls in.
- Replace the failed part, or the controller if all else tests good.
- Hot gas valve and contactor circuits are line-voltage and part of the refrigeration system.
- Probe adjustment needs the manual's data.
- Chipping at ice on the evaporator can puncture it.
How error code 50 differs from similar codes
Code 10 and Code 50 are both limited to Rev 1.1 to 1.5; Code 50 is about time and Code 10 about evaporator temperature.
Technical reference
- Maker documentation
- Kold-Draft owner support
- Edition
- Copyright 2015 Kold-Draft International; file named 'new 60 Series Service Manual rev041317' (Kold-Draft says it may not be current)
- Models / control
- Kold-Draft 60 Series electronic controller (K4B boards, revisions 1.1 to 1.80)
- Section
- Controller - Fault Codes (revision notes, pp. 21-22) and ERROR-CODE TROUBLESHOOTING (p. 23 onward)
- 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 Kold-Draft ice machine error codes
Is Code 50 on every K4B board?
No, only on Rev 1.1 to 1.5.
What replaced it?
A five-minute maximum defrost on Rev 1.6 and higher.
Can I just reset it?
The reset clears the code, but the cause remains.
Need help with Kold-Draft error code 50?
A technician confirms the cause on site and gives you the price in writing before any work starts.