Speed Queen Commercial Washer Error Code EC:20: Unreadable Card

What does Speed Queen error code EC:20 mean?

EC:20 is a card error on Speed Queen/Alliance commercial automatic washers. The display text is "Unreadable Card," and the manual's error listing says the reader could not read the card chip. It gives the cause as a bad card or dirty contact, and the action is to clean the chip on the card or the reader contacts and try the card again. If the error persists, the card may be bad. A smart card carries its data on a small chip, and the reader makes electrical contact with that chip to read it. Dirt, grease or wear on either side breaks the contact, and then the reader gets nothing at all. This differs from a read that arrives damaged: here nothing usable arrives. The manual gives no number of tries and does not say what a bad card looks like. A good test is to try a second card. If other cards read normally, the first card is the problem; if none read, the reader contacts or the reader itself needs attention.

Affected models and control systems

Speed Queen/Alliance commercial automatic washers covered by manual H002C: EDC (Micro-wand IIIe) models, MDC models and NetMaster models. The code is read from the card-reader (smart card) side of these controls, and the model numbers are listed on page 6 of the manual.

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

• The display shows "Unreadable Card" (EC:20)
• The card is inserted but nothing happens
• The card chip looks dirty or scratched

Possible causes

Likely causes — what usually sits behind error code EC:20 on this control. A technician confirms which one it is before any part is replaced.

• Bad card
• Dirty contact on the card chip or the reader
• Detergent film, lint or hand grease on the card chip blocks the contact
• Worn gold contacts on an old card no longer touch the reader pins
• The reader contact pins are bent or coated, so they do not reach the chip

Safe checks before calling for service

How a technician diagnoses error code EC:20

1. Read the code and ask if it happens with one card or all.
2. Test with a known good card.
3. Inspect and clean the reader contacts.
4. Check the reader connection and supply.
5. Replace the reader only if good cards still fail.

How error code EC:20 differs from similar codes

EC:09 is a related reader error where data arrives but is damaged. EC:20 is the case where the chip cannot be read at all.

Technical reference

Document

Commercial Automatic Washer (Metered and Nonmetered) Troubleshooting H002C

Edition

Part No. 39201R9, November 2016

Models / control

Speed Queen/Alliance commercial automatic washers H002C: EDC (Micro-wand IIIe) models, MDC models, NetMaster models (model numbers p. 6)

Section

32. EDC Error Code Listing, printed p. 59 (PDF p. 61); 41. MDC Error Code Listing, printed p. 72 (E:dr, E:FL, EC:19); 50. NetMaster Error Code Listing, printed pp. 90-93 (PDF pp. 92-95)

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.