Dexter Commercial Dryer Error Code F1: Temperature Sensor Shorted
F1 on a Dexter T-series dryer control means the temperature sensor is shorted. The dryer will not start until the short is removed, and F1 stays displayed until the programming button is pressed. Power down, clean the lint screen, and call us if F1 returns.
Medium: the dryer will not start until the short is cleared, though the usual causes are inexpensive to correct.
What does Dexter error code F1 mean?
The dryer control reads heat through a temperature probe mounted in the airflow under the basket. The probe's resistance changes with temperature, and the control converts that into a reading. If the probe or its wiring shorts, the resistance drops to almost nothing, which the control reads as impossible. Rather than guess at a temperature, it blocks the start and displays F1. The message is latched: Dexter's document says it remains on the display until the programming button is pressed, so clearing the cause is not enough on its own. Attendants usually see F1 sitting where the cycle display should be, and customers see a dryer that will not take a start. This is the mirror image of the open-sensor code on the same control. A short is often physical rather than electrical aging: a wire pinched against the cabinet, a connector that has been crushed, or lint and moisture bridging two terminals. That is why the checks begin with the area around the probe rather than the control board itself.
Affected models and control systems
Dexter T-30, T-50, T-80 and T-120 coin dryer controls, such as the T-50. Controls from other generations do not share this meaning.
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
- F1 stays on the display and the dryer will not start
- Pressing start does nothing
- The code returns right after the programming button clears it
- The dryer was working until a repair or cleaning near the basket
Possible causes
Listed in Dexter's documentation
- Shorted temperature probe under the basket
- Pinched probe wire or damaged probe connector
- Lint or moisture bridging the probe terminals
- Control input misreading the probe as shorted
Other likely causes — what usually sits behind error code F1 on this control. A technician confirms which one it is before any part is replaced.
- A harness that was repositioned during a belt or lint service and now touches sheet metal
- Damp lint packed around the probe after a leaking washer or wet floor nearby
Safe checks before calling for service
- At the disconnect, power the dryer off and wait for it to cool.
- Empty and clean the lint screen.
- Keep your hands off the wiring and the panels.
- Switch power on and press the programming button as the maker describes.
- If F1 returns, tell us what service was done recently and call us.
How a technician diagnoses error code F1
- Confirm F1 on the display and clear it with the programming button to see if it relatches.
- With power off and locked out, measure the probe resistance and compare it with its rating.
- Inspect the probe, its wire path and its connector for pinching, crushing and bridging debris.
- Disconnect the probe and check that the control no longer reads a short.
- Replace the probe or harness, or the control, only after the readings show which one is bad.
- The probe sits under the basket, so reaching it means opening panels near live dryer wiring.
- A shorted probe, a pinched wire and a control input problem all give F1, and separating them takes resistance readings.
- The programming button clears the message only; it does not show why the circuit shorted.
How error code F1 differs from similar codes
On the same control F2 reports an open sensor circuit; F1 reports a short, and F1 must be cleared with the programming button.
Technical reference
- Document
- Dexter Common Dryer Troubleshooting and Error Codes (Dryer Error Codes, p. 6)
- Maker documentation
- Dexter owner support
- Models / control
- Dexter T-30, T-50, T-80 and T-120 coin dryer control
- Section
- Dryer Error Codes table (Symptom / Probable Cause / Suggested Remedy), p. 6
- 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 Dexter dryer error codes
Why does F1 stay after I fix the problem?
The code is held on the display until the programming button is pressed, so it must be cleared by hand.
Can I run the dryer anyway?
No. The control will not start while it reads a short.
Is it the same as F2?
No. F2 is an open sensor circuit, and the test for it is different.
Need help with Dexter error code F1?
A technician confirms the cause on site and gives you the price in writing before any work starts.