UniMac Washer-Extractor Error Code Eio 36: Lock Pulse Hardware
Eio 36 reports a failed check of the door lock solenoid pulse hardware on the input and output board. It is the hardware side of Eio 31. Switch off the machine, stay out of the drum area, and call us.
High: the board may be unable to engage the lock, so the cycle cannot run safely.
- Code
- Eio 36
- 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 36 mean?
Eio 36 is the hardware side of Eio 31 on a UniMac QN washer-extractor. Where Eio 31 reports the pulse pin, Eio 36 reports that the pulse hardware on the input and output board failed its check. That circuit sends the short burst of current that moves the door lock into place. If the pulse circuit cannot be trusted, the board may not be able to engage the lock, so the control ends the cycle and holds the code until the board and lock have been tested. The manual lists a failed pulse stage on the board, a door lock solenoid or its wiring that disturbs the pulse circuit, a loose or corroded connector where the lock harness meets the board, and an I/O board that cannot pulse the lock and needs replacing. The distinction matters for the repair. A bad solenoid can damage the pulse stage, and a replacement board will fail again if the solenoid is the real source.
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 36 is the hardware check that pairs with Eio 31.
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 36 on the display and the cycle ended
- Door that does not latch at start
- A missing click from the lock
- Code held after a power cycle
Possible causes
Listed in UniMac's documentation
- A failed pulse stage on the input and output board
- A door lock solenoid or its wiring that disturbs the pulse circuit
- A loose or corroded connector where the lock harness meets the board
- An input and output board that cannot pulse the lock and needs replacing
Other likely causes — what usually sits behind error code Eio 36 on this control. A technician confirms which one it is before any part is replaced.
- A solenoid with a partly shorted winding that pulls too much current each pulse
- A harness worn open where the door closes on it repeatedly
- Moisture in the lock connector that leaks the pulse to ground
Safe checks before calling for service
- Make a note of Eio 36 and what the door did.
- Switch off the machine and let the drum stop.
- Do not reach into the drum area.
- Call us so we can test the pulse circuit.
How a technician diagnoses error code Eio 36
- Read the code and check for other Eio codes stored with it.
- With power locked out, inspect the lock harness and connector for moisture, corrosion and wear.
- Measure solenoid coil resistance and check for leakage to ground.
- Check the pulse stage on the board with the proper test.
- Replace the failed part, solenoid first when it is the source, before fitting a new board.
- Pulse tests use live control voltage and need a meter and the proper procedure.
- A damaged solenoid can destroy a replacement board, so the source must be proven first.
- Reaching into a drum to check the latch is an injury hazard.
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 does the solenoid matter if the board failed?
A shorted solenoid can damage the pulse stage, so replacing the board alone may not solve it.
Can I use the washer with a different door?
No. The lock circuit is part of this machine's control.
Is Eio 36 the same as Eio 31?
Eio 31 is the pulse pin. Eio 36 is the pulse hardware.
Need help with UniMac error code Eio 36?
A technician confirms the cause on site and gives you the price in writing before any work starts.