York TM9V080B12MP11 Error Code 2 Red Flashes: Pressure Switch Stuck Closed
What Does Code 2 Red Flashes Mean?
A 2 red flash code on the York TM9V080B12MP11 means the pressure switch contacts are closed at the start of a heat cycle when they should be open. The control board verifies the pressure switch is open before starting the inducer motor — if it reads as already closed, the board cannot trust the venting verification process and blocks the ignition sequence entirely.
A faulty pressure switch with stuck contacts is the most common cause. The switch's internal diaphragm and contact mechanism can wear out over thousands of cycles, eventually keeping the contacts permanently closed. Incorrect wiring of the pressure switch, particularly after a recent replacement or service visit, can also produce this reading by creating an unintended electrical path.
A qualified HVAC technician must diagnose this condition. The repair involves testing the pressure switch with a multimeter, inspecting the wiring connections for shorts or incorrect hook-up, and replacing the switch if its contacts are stuck. The pressure switch is a safety device and must never be bypassed.
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Faulty pressure switch stuck in closed position | Most common | ✗ Call a pro → |
| Miswiring of pressure switch | Common | ✗ Call a pro → |
When to Call a Professional
Contact a licensed HVAC technician if:
- When this code appears — a stuck pressure switch requires professional testing and replacement
✓ Verified against manufacturer service manual — March 2026