E1 Low-fire pressure switch stuck closed

What the control is telling you

The control sees the low-fire pressure switch already closed before the inducer has started, so it will not begin the ignition sequence. A blocked vent can also trigger this; the safety logic shuts the furnace off.

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

Likely causes

• Low-fire pressure switch contacts welded/stuck closed
• Loose or mis-wired pressure switch leads
• Blocked vent/exhaust pipe
• Faulty control board

Test and repair steps

1. Warning: Kill 115 V power and discharge static to bare furnace metal before touching the control or wiring.
2. Inspect the vent/exhaust pipe for obstructions and clear any blockage.
3. Check the pressure switch wiring for loose terminals or wrong connections; correct per the wiring diagram.
4. With the inducer off, disconnect the low-fire pressure switch leads and measure resistance across its two terminals - it should read open (infinite).
5. If the switch reads closed (continuity) at rest, replace the pressure switch.
6. If the switch reads open and wiring is correct but E1 persists, replace the control board.