Carrier 90% Gas Furnace: 58MXA

Re: Flashing Code 12 / Fault Code 12

Code 12 = Power present on "W" at power-up.

Diagnostic Light Sequence: 1-Short Flash, 2-Long Flashes (- , — —)

► This is a "Status" indication not a "Fault".

In case the furnace was in the process of heating when power was lost, the control board will run the blower motor for 90 seconds if "W" is calling when power is restored. During this period the board will flash a Code 12.