Kelvinator furnace shows E12 and the inducer runs continuously without ignition

Safety first: Turn OFF power before disconnecting any pressure tubing or wiring.

• Inspect tubing routing: Verify the rubber tube from the inducer housing goes directly to the pressure switch port and is not tee'd into other devices incorrectly.
• Check for water in tubing: Remove the tube from the pressure switch and inducer. Blow through it to clear any condensate. Reinstall securely.
• Tap pressure switch: With power OFF, lightly tap the pressure switch body to free a stuck internal contact.
• Restart furnace: Restore power and call for heat. If the inducer still runs without progressing to ignition and E12 remains, the pressure switch may be stuck closed and should be replaced.
• Board check: If a new pressure switch does not resolve the issue, the control board input circuit may be faulty and require replacement.