If a Samsung washing machine shows **tSt**, the verified Samsung meaning in this research set is **test mode**. Use the code to narrow the diagnosis, then confirm the exact model because code scope can change by product generation or region. Samsung uses overlapping code conventions across model years and regions. This page keeps the appliance context attached to the code so a same-looking string from another product family is not misapplied. The recorded display form is **tSt**. Search normalization stores it as **TST** while preserving the characters a homeowner actually sees.
Content status: Verified
Test mode.
Model compatibility: Samsung can reuse or reformat codes across series and model years, so TST may mean something different on another appliance or generation. Confirm this against your model’s documentation and record your full model number before acting.
If a Samsung washing machine shows **tSt**, the verified Samsung meaning in this research set is **test mode**. Use the code to narrow the diagnosis, then confirm the exact model because code scope can change by product generation or region. Samsung uses overlapping code conventions across model years and regions. This page keeps the appliance context attached to the code so a same-looking string from another product family is not misapplied. The recorded display form is **tSt**. Search normalization stores it as **TST** while preserving the characters a homeowner actually sees.
These are simple, non-hazardous checks only. If anything is unclear, stop and contact a technician.
Important safety warning. Disconnect power and stop use for active leakage near electrical parts, smoke, burning smell, or repeated breaker trips. Do not bypass a safety device merely to see whether tSt disappears.
Service is not automatically required. Request diagnosis only if the status cannot be cleared as designed or normal operation does not resume. A repeatable tSt event is more useful diagnostically than repeated resets, because it shows when the test mode check is failing.
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Test mode.
You can try the one reset Samsung documents for the model, but **tSt** returning afterward means the condition still exists. Note the operating stage instead of cycling power repeatedly.
This entry is classified as a status, reminder, test, or diagnostic state in the cited Samsung documentation. Normal use is appropriate only when the model instructions confirm the state and the appliance behaves normally.
No. **tSt** tells you which condition or check the control detected. The same display can result from the named component, its wiring, a connector, a supply/airflow/water condition, or the control that reads it.
The same-looking code can be reused on another Samsung appliance family or reformatted by region/model year. Match the appliance type and exact model before applying a meaning. This page therefore keeps **Washer tSt** separate from same-looking codes used by other Samsung appliance families.
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