UniMac Washer Error Code Ed03: Tachometer Error
Ed03 on a UniMac UC-series washer-extractor with a motor drive is a tachometer error: the drive saw a damaged tach input at power-up or no tach signal once the motor started. Power down, make sure nothing leans on the machine, and retry. If Ed03 returns, leave the panels closed and call us.
High: the drive will not run the motor without speed feedback, so the machine cannot spin.
What does UniMac error code Ed03 mean?
On UniMac UC-series washer-extractors such as the UCH020GNF with the motor drive, Ed03 is a tachometer error. The tachometer, or tach, is a sensor on the motor that sends pulses to the drive so it knows how fast the motor is turning. The drive checks the tach input when it powers up. If it finds the input damaged, or if it sees no pulses after it has started the motor output, it cannot control speed and stops the cycle. Running a motor without speed feedback is not safe, so the drive does not try. The manual lists a tach wire or connector that is loose at the motor, a drive tach input labeled H3 that is damaged, a motor tach sensor that sends no pulses, and a drive board that cannot read the signal. Only Design 2 and 3 machines show this code.
Affected models and control systems
Listed for UniMac UC-series washer-extractors with a motor drive (CHM495R family, 20-100 lb), such as the UCH020GNF, Design 2 and 3 only. The tach input on the drive is labeled H3.
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
- Ed03 on the display and the cycle stops at spin or tumble start
- Motor tries to start, then stops
- Code appears immediately at power-up on some machines
- Drum does not reach its usual speed
Possible causes
Listed in UniMac's documentation
- Tach wire or connector loose at the motor
- Drive tach input labeled H3 damaged
- Motor tach sensor that sends no pulses
- Drive board that cannot read the tach signal
Other likely causes — what usually sits behind error code Ed03 on this control. A technician confirms which one it is before any part is replaced.
- Tach cable chafed where it leaves the motor housing after years of vibration
- Moisture or lint packed in the tach connector at the motor
- A motor replaced earlier with the tach lead left poorly seated
Safe checks before calling for service
- Power the machine down.
- Make sure nothing is leaning on the machine and the drum can move freely by its own cycle.
- Do not remove panels to chase connectors.
- Power up and retry. If Ed03 returns, call us.
- Note whether Ed03 shows at power-up or only after the motor tries to run.
How a technician diagnoses error code Ed03
- Read the code and note when it appears: at power-up or after the motor starts.
- With power locked out, inspect the tach wire and connector at the motor and at the drive's H3 input.
- Check the tach sensor's output while the motor shaft turns, using the manual's values.
- Check the drive input for damage and compare readings with the wiring diagram.
- Replace the tach lead, motor or drive only after the signal tests.
- The motor and drive carry 208-240 V, and testing the tach means working next to the motor with the drive's stored charge to respect.
- Telling a bad tach sensor from a damaged drive input takes a signal test with the shaft turning.
- The machine must not be run without speed feedback, so the repair needs to be verified under controlled test.
How error code Ed03 differs from similar codes
Ed03 is about missing speed feedback. Ed04 is about a motor that does not reach speed, and E ro is the drum rotation sensor on pocket hardmount machines.
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
What does the tach do?
It tells the drive how fast the motor is turning, so the drive can control speed and braking.
Will Ed03 clear after a restart?
It might if a connector was marginal. If it comes back, the tach circuit needs testing.
Does Ed03 mean a new motor?
Not necessarily. Many tach problems are a connector or a wire, and we test before replacing parts.
Need help with UniMac error code Ed03?
A technician confirms the cause on site and gives you the price in writing before any work starts.