HVAC Code Lookup

Coleman Furnace 2 Red Flashes

Soft lockoutShown as: Two red flashes, then a two-second pause, repeating

The pressure switch is closed when it should be open. Before each heat cycle the control checks the pressure switch contacts are open; if they are already closed it will not allow the ignition sequence to start.

Manual wording: “2 RED FLASHES: This indicates that the pressure switch is closed when it should be open... Check for a faulty pressure switch or miswiring.”

Documented for: TG8S, TGLS, TG9S, TM8X, TMLX, TM9X, TM8T, TM9T, TM8V, TM9V

Likely causes, most common first

  1. Faulty pressure switch stuck closed
  2. Miswired pressure switch

What you can safely check yourself

  • Turn the furnace off at the service switch for a minute and back on once to see whether the code clears

When to call a technician

A stuck-closed pressure switch is a safety interlock failure. It must be tested and replaced by a technician - never jumper or bypass it.

A Coleman furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.

Sources

Other Coleman codes