Samsung Dryer tO Error — Temp Sensor Open Fix

What it means

Samsung dryer tO is the temperature-sensor-open code (the 'tO' is a letter T followed by a capital O, not the number zero).
Samsung groups this with the same family as tS: 'These reflect an issue with the temperature or with the sensors that measure it.'
Same first-line fix: clean the lint screen and exhaust vent before suspecting the sensor itself.

Affected Models

Samsung DVE45 / DVE50 / DVE52 series electric dryers
Samsung DVG45 / DVG50 / DVG52 series gas dryers
Samsung DV9000T / DV9100T Smart Dial series
Samsung BESPOKE AI laundry dryers
Samsung FlexDry and WashTower units (shared dryer module)

Common Causes

Lint screen so clogged that airflow drops out of operating range
Exhaust vent blocked or pinched — heat trapped in drum
Thermistor wire connector loose (often after a recent service visit)
Open circuit in the thermistor harness (chewed wire, vibration damage)
Failed thermistor (only confirmed after lint and vent are clean)

How to Fix It

Clean the lint screen first.

This is Samsung's universal first step for temperature codes.
Pull the screen out, brush off lint by hand, and if you use dryer sheets, rinse under warm water every 2-3 months to remove residue that builds up invisibly.
Vacuum the exhaust vent.

Disconnect the flex duct from the back of the dryer, vacuum out the dryer's port and the duct.
Walk outside and confirm the wall vent flap opens freely when the dryer runs.
Lint accumulates at the outdoor termination over months.
Run the Vent Blockage test if supported.

Samsung's exact procedure: 'Press POWER to turn the dryer on and within 5 seconds, press and hold Adjust Time Up + Dry Level until InS or In appears.'
The 2-minute test reports the blockage percentage so you know exactly where you stand.
Power cycle for 1 to 5 minutes.

Samsung's published reset: 'Unplug it (or turn off power at the circuit breaker), wait some time for the electrical charge to clear out of the dryer (usually 1 to 5 minutes at most), and then power it up again.'
Schedule service if tO returns.

If lint and vent are confirmed clean and tO reappears, the thermistor wiring or sensor itself needs service.
This isn't an owner repair on modern Samsung dryers — the harness routes through the cabinet and the thermistor sits on the heating duct.

When to Call a Professional

Same call-service rule as tS: only after lint screen, exhaust vent, and a power reset have been done, AND tO returns, is the temperature sensor likely failed and needing service.

Frequently Asked Questions

Why are there two similar-sounding codes (tS and tO) for the same kind of fault?

Samsung's control distinguishes between a temperature sensor reading as SHORTED (tS — too low resistance, suggests wire-to-wire contact) and OPEN (tO — infinite resistance, suggests disconnected or broken wire).
Internally they're different fault states, but for owner troubleshooting both clear with the same lint and vent cleaning, then a power reset.
The technician's diagnostic reader confirms which sensor or wire failed if cleaning doesn't help.