IPSO Tumble Dryer Error Code AF-2: Airflow Switch Did Not Close
AF-2 on an IPSO 120/170 lb tumble dryer means the airflow switch did not close after the cycle started, so the control kept the heat off. Stop the dryer and check whether the lint screen is packed. If you smell gas, clear the room and call the gas utility from outside.
High: the dryer will not heat, and the cause is a safety-related air path.
- Code
- AF-2
- Maker
- IPSO
- Equipment
- Industrial laundry
- Applies to
- Tumble dryers 120/170 lb (TMB1268C family) micro control
What does IPSO error code AF-2 mean?
After the cycle starts, the blower begins pulling air through the drum and out the exhaust. That moving air pushes the airflow switch closed, and the control waits for that closure before it permits heat. If the switch has not closed within the expected time, the control concludes that air is not moving properly and posts AF-2. The dryer tumbles but never heats. Low airflow from a clogged lint screen, a blocked exhaust duct, a blower that is not moving air, or a failed switch are typical causes. A shortage of make-up air to the room also starves the blower. In a hot, humid season, a dryer room with sealed doors can feel like the blower is working while the dryer sees almost no air. Unlike AF-1, the switch here is probably doing its job honestly. The air is not arriving.
Affected models and control systems
IPSO 120/170 lb tumble dryers in the TMB1268C family with the micro control. Other controller generations 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
- Drum tumbles but the load stays cold
- AF-2 on the display shortly after start
- Lint screen heavily loaded
- Dryer room very warm with weak air at the exhaust
Possible causes
Listed in IPSO's documentation
- Lint screen and exhaust duct restricted
- Blower and its drive not moving air
- The airflow switch and its wiring
- Make-up air to the dryer room too low
Other likely causes — what usually sits behind error code AF-2 on this control. A technician confirms which one it is before any part is replaced.
- Exhaust duct crushed or disconnected behind the dryer
- Outside hood flap stuck or clogged with lint
- Blower wheel loose on its shaft
- Switch vane stuck open by lint
Safe checks before calling for service
- If you smell gas, clear the room at once and call the gas utility from outside.
- Otherwise, stop the dryer and see whether the lint screen is packed.
- Do not hold, tape or bypass the switch.
- Ask us to check the airflow path, and tell us how long the duct run is.
How a technician diagnoses error code AF-2
- Read the code and confirm AF-2 occurs with heat requested.
- Check the lint screen, exhaust duct and outside hood for blockage.
- Verify blower rotation and wheel condition with power locked out.
- Test the switch vane travel and continuity with air flowing.
- Confirm make-up air, then replace the switch only if it fails with good airflow.
- The blower and drive run on live 208-240 V circuits, and the burner area contains gas fittings. Duct cleaning on a long run involves heights and fire risk. Judging airflow takes manometer or damper work, not guesswork.
How error code AF-2 differs from similar codes
AF-2 differs from AF-1, where the switch was already closed before start, and from a flashing AF, where it cycles open and shut repeatedly.
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
- Tumble dryers 120/170 lb (TMB1268C family) micro control
- 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 IPSO industrial laundry error codes
Can I keep running the dryer after AF-2?
No. Without proper airflow the control stops the heat to prevent overheating.
Will cleaning the lint screen fix AF-2?
It can, if the screen was the restriction. If not, the duct or blower is next.
What if AF-2 comes back after a clean?
The switch, blower or duct needs testing by a technician.
Need help with IPSO error code AF-2?
A technician confirms the cause on site and gives you the price in writing before any work starts.