UniMac Washer-Extractor Error Code Eio 37: Lock Output Full Hardware
Eio 37 is the broadest of the door lock hardware codes: the input and output board tested the whole lock output path and it did not pass. The control ends the cycle, so shut the washer off, never force the door, and call us.
High: the whole lock output path failed its check, so the washer must stay off until it is tested.
- Code
- Eio 37
- Maker
- UniMac
- Equipment
- Industrial laundry
- Applies to
- CHM1792C family washer-extractor (QN models, 20-100 lb) front-end control
What does UniMac error code Eio 37 mean?
Eio 37 is the broadest of the door lock hardware codes on a UniMac QN washer-extractor. The other lock codes name a single pin, pulse or output stage. For Eio 37, the input and output board tested the entire lock output path, covering the pin, the pulse and the output together, and it did not pass. The result is the same as for the narrower codes: the board cannot promise to hold or release the door, so the control ends the cycle and holds the code. The board will probably need attention from a technician before the washer is used again. The manual lists the complete lock output on the I/O board, the solenoid coil and harness, the board power supply, and whether a new board is required at all. Because the whole path failed, a low or unstable board supply is worth ruling out along with the lock parts. Write down what the door did, switch off, wait for the drum to settle, and keep the area dry and clear.
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. Eio 37 is the all-in-one lock output check among the lock-related hardware codes.
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
- Eio 37 on the display and the cycle stopped
- Door that will not latch or will not release
- No clicking from the lock
- Other Eio codes appearing alongside it
Possible causes
Listed in UniMac's documentation
- Complete lock output on the I/O board
- Solenoid coil and harness
- Board power supply
- If a new board is required at all
Other likely causes — what usually sits behind error code Eio 37 on this control. A technician confirms which one it is before any part is replaced.
- A board supply that dips when the lock draws current, which fails every lock check at once
- A solenoid shorted so badly that it overloads the pin, pulse and output together
- Water in the lock connector bridging several lock circuit lines
Safe checks before calling for service
- Write down Eio 37 and what the door did.
- Shut off the washer and wait for the drum to settle.
- Never force the door.
- Call us and tell us the code and the model, and keep the area dry and clear.
How a technician diagnoses error code Eio 37
- Read the code and see whether other Eio lock codes are stored with it.
- Measure the supply to the I/O board with the lock energized and idle.
- With power locked out, inspect the lock harness and test the solenoid coil.
- Check the lock output on the board against the maker's procedure.
- Replace the board or solenoid only once the failed element is proven.
- A failing lock path makes the door interlock unreliable, which is a personal safety matter.
- Supply measurements on the board are taken near live control and mains-powered circuits.
- Distinguishing a board from a solenoid failure needs a meter and the maker's specification.
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
Why is this code broader than the others?
It covers the complete lock output path rather than a single pin or stage.
Does it need the whole board replaced?
Not necessarily. The solenoid and harness can be the cause, so we test them first.
Can I keep using the washer?
No. The cycle ends because the lock cannot be relied on.
Need help with UniMac error code Eio 37?
A technician confirms the cause on site and gives you the price in writing before any work starts.