Cissell Dryer Error Code AF-1: Airflow Switch Closed at Start
AF-1 means the airflow switch was already closed when the cycle started, which is wrong because it should stay open until the blower moves air. The control refuses to heat and the drum stays cold. Switch the dryer off, clean the lint screen and lint door area, check the outside vent opening, then try one cycle.
Medium: the dryer will not heat until the switch reads correctly, but nothing is damaged by waiting.
What does Cissell error code AF-1 mean?
Before a Cissell dryer lights its heat, the control wants proof that air is moving through the drum and out the vent. An airflow switch in the exhaust path supplies that proof. It is built to rest open while the blower is off and to close only when moving air pushes it. On the 120 and 170 lb micro control dryers, such as the CT120N and CT170N, the control also looks at the switch as the cycle begins. If it already reads closed before the blower has run, the reading cannot be trusted, so the control will not allow heating and shows AF-1. The drum may still turn, which is why a cold, damp load is often the first sign. This is the opposite of the AF-2 message, where the switch fails to close once air is flowing. AF-1 is most often a switch held shut by lint or a binding pivot, or a wire or input reading the switch wrongly.
Affected models and control systems
This page covers the Cissell 120 and 170 lb tumble dryers with the micro control, C-prefix models, as listed in the Troubleshooting manual. Other Cissell controls use different codes.
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
- Display shows AF-1 as soon as a cycle starts
- Drum turns but the load stays cold and damp
- No heat comes on even after the lint screen is cleaned
Possible causes
Listed in Cissell's documentation
- An airflow switch stuck in the closed position
- Lint packed around the switch
- Damaged airflow switch wiring
- A control input that misreads the switch
Other likely causes — what usually sits behind error code AF-1 on this control. A technician confirms which one it is before any part is replaced.
- A switch arm that has been pressed shut by a clump of lint that dried on it
- A switch pivot that has gone stiff from moisture and dust after the dryer sat unused
- A wire pair at the switch that has been pinched together so the circuit reads closed all the time
Safe checks before calling for service
- Switch the dryer off and let it stand.
- Clean the lint screen and the lint door area.
- Check that the outside vent opening is clear of lint or debris.
- Restore power and start a cycle. If AF-1 shows again, note whether it came up right at the start and call us.
How a technician diagnoses error code AF-1
- Read the code and confirm that it comes up before the blower has run.
- Inspect the airflow switch and its pivot for lint, binding and bent parts.
- Measure the switch at rest, with the blower off, for an open circuit.
- Check the wiring and the control input reading the switch.
- Replace the switch or the control only after the rest reading proves which one is wrong.
- The airflow switch sits in the exhaust path behind panels on a machine with line-voltage wiring.
- A switch that reads closed at rest can only be proven with a meter.
- Bypassing the airflow proof would remove the protection that stops the heat from running without exhaust.
How error code AF-1 differs from similar codes
AF-2 is the reverse case, where the switch fails to close after the cycle starts. A flashing AF means the switch toggled five or more times during a cycle.
Technical reference
- Document
- Tumble Dryers 120/170 lb Troubleshooting TMB1268C, Part No. 70399901R2, Dec 2016 (pp.53, 65)
- Edition
- Part No. 70399901R2, December 2016; models through serial no. 0907000048
- Models / control
- 120/170 lb tumble dryers micro control (C-prefix models)
- Section
- Hybrid Timer Control Troubleshooting - 31. Error Codes, printed p. 53 (PDF p. 55); On Premise Micro Control (RM) Troubleshooting - 36. Error Codes, printed p. 65 (PDF p. 67)
- 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 Cissell dryer error codes
Can I keep using the dryer with AF-1 showing?
No. The control will not heat, so the load will not dry. Cleaning the lint is safe, but the dryer should be checked if the code returns.
Will AF-1 clear by itself?
It may after a power-off pause if lint was the cause. If it returns at the next start, the switch or wiring needs a test.
Is AF-1 the same as AF-2?
No. AF-1 means the switch is closed too early, AF-2 means it never closes once the blower is running.
Need help with Cissell error code AF-1?
A technician confirms the cause on site and gives you the price in writing before any work starts.