HVAC Code Lookup

Coleman Furnace 6 Red Flashes

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

While the furnace was running, the pressure switch opened four times during one call for heat. The furnace locks out for one hour, then tries again on its own.

Manual wording: “6 RED FLASHES: This indicates that while the unit was operating, the pressure switch opened four times during the call for heat. Check for faulty inducer, blocked vent pipe or faulty pressure switch. The furnace will lock out for one hour and then restart.”

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

Likely causes, most common first

  1. Faulty inducer (draft) motor
  2. Blocked vent pipe
  3. Faulty pressure switch

What you can safely check yourself

  • Check the outside vent and intake pipe terminations for snow, ice, leaves or nests
  • Check the condensate drain and trap for a clog
  • Replace a dirty air filter

When to call a technician

If the pipes are clear and the furnace keeps dropping out, the inducer or pressure switch is failing and needs a technician.

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

Sources

Other Coleman codes