UniMac Washer Error Code Err: Coin Error
Err on a UniMac UC-series washer-extractor is the coin error: the coin or card-pulse input saw an invalid coin pulse, or the coin sensor is not working at all. The washer cannot tell it was paid and will not accept the start. Remove any jammed coin you can see, restart, and try one clean coin.
Medium: the machine will not accept a start until the coin input works.
What does UniMac error code Err mean?
On UniMac UC-series washer-extractors such as the UCH020GNF, Err is the coin error. A vended washer counts coin or card pulses before it will start. The coin or card-pulse input to the control saw an invalid coin pulse, or the coin sensor is not working at all. The washer cannot tell it was paid, so it will not accept the start. This is a vending-input problem and not a wash-system problem, so the water, drain and drive circuits are usually fine. A bent coin or a jam in the coin slide is a common reason, since the pulse can arrive distorted or not at all. The manual lists the coin drop or coin sensor connection, the coin pulse wiring to the control, bent or jammed coins in the coin slide, and the control input for the pulse signal.
Affected models and control systems
Listed for UniMac UC-series washer-extractors in the CHM495R family (20-100 lb), such as the UCH020GNF, front-end control with the coin input.
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
- Err on the display after a coin is inserted
- The machine does not start after payment
- Coins drop through but no credit shows
- Nothing else about the wash is affected
Possible causes
Listed in UniMac's documentation
- Coin drop or coin sensor connection
- Coin pulse wiring to the control
- Bent or jammed coins in the coin slide
- Control input for the pulse signal
Other likely causes — what usually sits behind error code Err on this control. A technician confirms which one it is before any part is replaced.
- Foreign objects or lint in the coin slide from customers
- A worn coin sensor that misses coins of one size
- Moisture on the coin drop connector from a wet floor or spray
Safe checks before calling for service
- Remove any jammed or bent coin you can see in the coin slide without opening the cabinet.
- Power the machine down and up again, then try one clean coin or the normal payment.
- Leave the control cabinet closed.
- If Err keeps showing, call us so we can check the sensor and wiring.
- Note which coin or card you used.
How a technician diagnoses error code Err
- Read the code and test with a known good coin.
- Inspect the coin slide and drop for jams, wear and debris.
- Check the coin sensor, its connector and the wiring to the control with the power locked out.
- Measure the pulse signal at the control input while a coin passes.
- Replace the sensor, wiring or control input only after the pulse test.
- The coin mechanism sits next to the control, and its cash box and wiring should only be opened by trained staff with the power off.
- A bad sensor, a pinched wire and a weak control input look the same without a pulse test.
- Opening the coin area exposes the money box, which the owner should control.
How error code Err differs from similar codes
Err is a vending input problem on UC machines. It does not relate to the E-prefixed wash and drive codes.
Technical reference
- Document
- Washer-Extractor Programming CHM495R_SVG, Part No. F8208501ENR10, March 2017, Error Codes (pp. 36-37)
- Maker documentation
- UniMac owner support
- Edition
- Part No. F8208501ENR10, March 2017
- Models / control
- CHM495R family washer-extractor front-end control (20-100 lb)
- Section
- Error Codes table, pp. 36-37 (E Pr only on Design 1 models; Ed01-Ed11 on Design 2 and 3 models)
- 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
Is Err a wash problem?
No. It is about the coin input, and the wash circuits are usually fine.
Why does a bent coin cause it?
The pulse it produces can be invalid or missing, which the control reads as an error.
Will a restart clear Err?
It clears the display, and a clean coin may work. If not, the sensor needs a check.
Need help with UniMac error code Err?
A technician confirms the cause on site and gives you the price in writing before any work starts.