E5 Limit/rollout switch open less than 5 minutes

What the control is telling you

A high-limit or flame-rollout switch opened and re-closed within 5 minutes. Usually overheating from poor airflow; a rollout trip can mean a venting/combustion problem.

Applies to: Midea BGH96M 96% AFUE two-stage gas furnaces (060B3A, 080B3A, 080C4A, 100C5A, 100D5A, 120D5A)

Likely causes

• Dirty filter or restricted ductwork
• Blower not starting or wrong speed tap
• Blower motor fault
• Wrong or failed limit switch
• Blocked exhaust / inducer problem (rollout)
• Loose wiring
• Faulty control board

Test and repair steps

1. Warning: Kill 115 V power and discharge static to bare furnace metal before servicing. Turn the furnace off for 10 minutes so the limits can cool before testing.
2. Check the air filter and clean/replace it if dirty; check the supply/return ductwork for blockage or closed registers.
3. Check for loose or wrong wiring at the limit and rollout switches; correct per the wiring diagram.
4. Confirm the blower starts about 30 s after the burners light and that there is power to the circulating motor (18-31 VAC speed signal from the board, 115 VAC between CIRC-H and N). If not, see the no-fan checks / replace the board or blower motor.
5. Verify the blower speed tap matches the model (air-delivery tables 4 and 5) and that temperature rise is within 40-55°F; correct the speed or replace the motor if needed.
6. Measure resistance across both the chamber-mounted limit (behind the gas valve) and the fan-mounted limit (side of the blower, behind the board): each should read 0 ohms when cool. Confirm the correct limit part for the model (inlet high limit 150°F off / 120°F on). Replace any that read open or are the wrong part.
7. Check the rollout switches (300°F, manual reset): press the reset button, then measure for 0 ohms. If a rollout keeps tripping after reset, find the cause before returning to service and replace the rollout switch if it will not hold.
8. Warning: A tripped rollout means flame has left the burner area - check the exhaust pipe for blockage and confirm the inducer works; replace the inducer if it does not.
9. If all switches, airflow and wiring check good and the code persists, replace the control board.