UniMac Washer Error Code Eio 35: Door Lock Output Hardware
Eio 35 on a UniMac QN washer-extractor is an I/O board hardware code saying the output stage that drives the door lock solenoid failed its check. The board cannot reliably power the lock, so the cycle stops. Record the code, power down and leave the lock and cabinet alone; it needs a technician.
High: the lock output cannot be relied on, so the cycle stops and the machine should stay off.
What does UniMac error code Eio 35 mean?
Eio 35 on UniMac QN washer-extractors such as the UCA020QN is an I/O board hardware code for the door lock solenoid hardware output. The output stage on the board is the part that drives current to the lock solenoid. The board tests it, and when the output stage failed its check, the board cannot reliably power the lock. The control stops the cycle and keeps the code until the board is serviced. A lock that powers up only sometimes would let the door release or latch unpredictably, which is why the stop is not skipped. The manual lists a failed output stage on the I/O board that drives the lock, a lock solenoid coil with a short or open winding, and a loose plug at the lock solenoid causing a poor output reading.
Affected models and control systems
Listed for the CHM1792C family of UniMac QN washer-extractors (20-100 lb), with the UCA020QN as the example model, on the input and output (I/O) board.
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 35 on the display and the cycle stops
- Door latches sometimes and not others
- No lock sound when a cycle is started
- Code returns every time
Possible causes
Listed in UniMac's documentation
- Failed output stage on the I/O board that drives the lock
- Lock solenoid coil with a short or open winding
- Loose plug at the lock solenoid causing a poor output reading
Other likely causes — what usually sits behind error code Eio 35 on this control. A technician confirms which one it is before any part is replaced.
- A solenoid coil that burned out after repeated locking against a bent door latch
- A plug at the lock with oxidized pins from steam
- An output stage damaged by a past voltage spike
Safe checks before calling for service
- Record Eio 35 and note whether the door latched.
- Power the machine down and wait for the drum to stop.
- Leave the lock and cabinet alone.
- Call us for a test of the lock output.
- Keep wet items out of the cabinet area.
How a technician diagnoses error code Eio 35
- Read the code and note the latch behavior.
- With power locked out, check the lock plug and wiring.
- Measure the solenoid coil for a short or open winding.
- Check the board's lock output voltage during a lock command.
- Replace the lock or the board depending on the failing test.
- The lock output is driven at line voltage, so the output check is made on an energized board.
- A coil with a short or open winding is found by measurement, not by looking.
- An unreliable door lock on a spinning machine is a hazard, so the repair needs to be verified with the door fully tested.
How error code Eio 35 differs from similar codes
Eio 35 is the lock output hardware. Eio 32 is the relay pin, Eio 31 the pulse pin, and Eio 34 the disable hardware.
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 washer error codes
Does Eio 35 mean the lock coil is burned out?
It can, since a shorted or open coil is on the manual's list, but the board output can fail too.
Can I tell which part failed?
Only by testing the coil and the output. We do this on the visit.
Is it safe to keep trying cycles?
No. Leave the machine off until the lock circuit has been tested.
Need help with UniMac error code Eio 35?
A technician confirms the cause on site and gives you the price in writing before any work starts.