American Dryer Error Code EXHAUST HIGH LIMIT FAULT: Exhaust Disk Open
EXHAUST HIGH LIMIT FAULT means the exhaust temperature disk on a Phase 7 American Dryer has opened because exhaust heat went too high, and the dryer cannot run until it is dealt with. Let it cool, empty the lint screen and look at the outdoor exhaust opening, then call us.
High: the dryer is stopped by a heat safety and will not run until the cause is fixed.
- Code
- EXHAUST HIGH LIMIT FAULT
- Maker
- American Dryer (ADC)
- Equipment
- Dryers
- Applies to
- Phase 7 OPL microprocessor controller (also Phase 6 on ML-175/190)
What does American Dryer (ADC) EXHAUST HIGH LIMIT FAULT mean?
Heat leaves a gas dryer through its exhaust, so the exhaust path carries a thermal disk that watches how hot that air gets. The disk is a safety switch: it stays closed in normal operation and opens if exhaust heat climbs past its rating. The Phase 7 control monitors the circuit, and when the disk opens it stops the dryer and displays EXHAUST HIGH LIMIT FAULT. The control does not decide anything here. It follows the disk, and the dryer stays stopped until the heat condition is dealt with. The manual's list explains why exhaust heat might climb: restricted exhaust or lint buildup that stops air carrying heat away, the disk itself, the balance between the burner and the airflow, and the control wiring to the disk. Operators see the dryer stop, often late in a heavy day of loads, with the message on the display. This is a different switch from the burner disk and from the basket temperature reading, so the cause is usually found in the duct, the lint path or the airflow balance.
Affected models and control systems
This applies to gas American Dryer tumblers with the Phase 7 OPL microprocessor controller, such as the AD-115 and AD-170, and the Phase 6 control on ML-175 and ML-190 models. 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
- The dryer stops and EXHAUST HIGH LIMIT FAULT stays on the display
- Drying times have been getting longer before the stop
- The laundry room feels hotter and more humid than usual
Possible causes
Listed in American Dryer (ADC)'s documentation
- Restricted exhaust or lint buildup
- Exhaust temperature disk has opened
- Burner and airflow out of balance
- Control wiring to the disk is open or damaged
Other likely causes — what usually sits behind EXHAUST HIGH LIMIT FAULT on this control. A technician confirms which one it is before any part is replaced.
- A long exhaust run to the roof that has collected lint at its bends and slowed the airflow
- A makeup air opening that is blocked, so the dryer starves for air and the exhaust heats
- A disk that has weakened with age and now opens below its normal temperature
Safe checks before calling for service
- Switch the dryer off and let it cool fully.
- Empty the lint screen and clean around the lint drawer.
- Look at the outdoor exhaust opening for blockage, and leave duct work to us.
- Do not reach for the disk yourself.
- Note how long the dryer ran and how long the exhaust run is, then tell us.
How a technician diagnoses EXHAUST HIGH LIMIT FAULT
- Read the message and test the exhaust disk for continuity with the dryer cold.
- Measure airflow and static pressure in the exhaust duct.
- Inspect the duct run, bends and outdoor cap for lint and damage.
- Check makeup air availability in the room.
- Check the burner input against the data plate and the wiring to the disk.
- Clear the restriction and replace the disk only if it tests bad, then run a full cycle.
- Cleaning an exhaust run and measuring its airflow need tools and often roof or wall access.
- The disk opened because exhaust heat climbed, so the cause lives in the duct and burner balance.
- Resetting it without fixing the airflow only leads to repeated stops.
How EXHAUST HIGH LIMIT FAULT differs from similar codes
EXHAUST HIGH TEMP FAULT on the same control is a separate message: it reports basket temperature above 220 F, while this one reports the exhaust disk opening.
Technical reference
- Document
- AD-115/120/170 ML-120/130/145/170 Service Manual, Phase 7 Microprocessor Controls (part 451102 R2), Diagnostic messages pp.43-44
- Maker documentation
- American Dryer (ADC) owner support
- Edition
- Part 451102 R2
- Models / control
- Phase 7 OPL microprocessor controller (also Phase 6 on ML-175/190)
- Section
- Diagnostic messages pp.43-44
- 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 American Dryer (ADC) dryer error codes
Is EXHAUST HIGH LIMIT FAULT the same as EXHAUST HIGH TEMP FAULT?
No. This one comes from the exhaust disk opening, and the other reports a basket temperature over 220 F.
Can I just reset it and finish the load?
Only after a full cool-down, and expect it to return if lint or ducting is the cause.
How often should the exhaust be cleaned?
It depends on volume, but a dryer that stops this way is overdue for a duct inspection.
Need help with American Dryer (ADC) EXHAUST HIGH LIMIT FAULT?
A technician confirms the cause on site and gives you the price in writing before any work starts.