UniMac Washer-Extractor Error Code EnXX: Machine ID Chip Not Read
EnXX means the machine ID chip cannot be read. Without it the control does not know the size or options to use, so the machine may refuse to start cycles correctly. Switch the machine off and on once, and call us if EnXX returns.
Medium: the machine may not start cycles correctly until the chip is read again.
- Code
- EnXX
- Maker
- UniMac
- Equipment
- Industrial laundry
- Applies to
- CHM1792C family washer-extractor (QN models, 20-100 lb) front-end control
What does UniMac error code EnXX mean?
A small chip in a UniMac QN washer-extractor, the Machine ID chip, tells the control which machine it belongs to. The control reads it at start-up to learn the size, options and settings that apply to this model. EnXX is shown when the chip cannot be read. The XX is a value pointing to the type of chip problem. Without the chip, the control does not know which machine it is running, so until the chip is read again the machine may refuse to start cycles correctly. The manual lists a user control that is not plugged firmly into the Machine ID chip, a chip that is loose in its socket or damaged, a wire near the chip that is broken or loose, and a user control board that cannot read the chip. The maker's own step is to switch the machine off and on and try once more. The chip must not be removed or swapped by anyone but a technician, because a chip from another machine gives the wrong settings.
Affected models and control systems
This applies to the CHM1792C family of UniMac QN washer-extractors, 20 to 100 lb, front-end control, for example the UCA020QN. The Machine ID chip is part of the user control, and EnXX applies to this front-end control.
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
- EnXX on the display at power-up
- Machine that will not start a cycle
- Cycles that run with the wrong settings
- Code that returns after a power cycle
Possible causes
Listed in UniMac's documentation
- A user control that is not plugged firmly into the Machine ID chip
- A chip that is loose in its socket or damaged
- A wire near the chip that is broken or loose
- A user control board that cannot read the chip
Other likely causes — what usually sits behind error code EnXX on this control. A technician confirms which one it is before any part is replaced.
- A chip socket contact that has oxidized and no longer makes a reliable connection
- A chip pulled partway out during an earlier service call
- A user control board that was swapped without moving the original chip
Safe checks before calling for service
- Switch the machine off and on and try once more, which is the maker's own step.
- Inspect the chip connection from the outside of the cabinet only.
- Do not remove or swap any chips.
- If EnXX returns, note the two characters after En and call us.
How a technician diagnoses error code EnXX
- Read the two characters after En and note when the message appears.
- With power locked out, inspect the Machine ID chip seating and the wire near it.
- Check the chip pins for corrosion or bending.
- Verify that the chip belongs to this machine's model and size.
- Replace the chip or user control only after seating and wiring are confirmed.
- The chip is on the user control board, and handling it risks static damage and wrong settings.
- A chip from another machine can load the wrong sizes and options and damage the machine in use.
- Checking board wiring means opening the control near live circuits.
Technical reference
- Document
- Washer-Extractor Programming CHM1792C_SVG, Part No. F8641001ENR4, Error Codes Table 29 (pp. 100-107)
- Maker documentation
- UniMac owner support
- Edition
- Part No. F8641001ENR4, January 2020
- Models / control
- CHM1792C family washer-extractor (QN models, 20-100 lb) front-end control
- Section
- Error Codes, Table 29, pp. 100-108 (PDF pages equal printed pages)
- 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 UniMac industrial laundry error codes
What does the Machine ID chip do?
It tells the control which machine it is and which options apply to it.
Can I swap a chip from another washer?
No. It would load the wrong settings and could cause damage.
Will a power cycle fix it?
Sometimes, if the chip was loosely seated. A repeat needs a technician.
Need help with UniMac error code EnXX?
A technician confirms the cause on site and gives you the price in writing before any work starts.