Goodman GMEC960803BN Error Code Red 3 Double Flashes: 2nd-Stage Pressure Switch Stuck Open / Inducer Error

What Does Code Red 3 Double Flashes Mean?

Three double red flashes on the Goodman GMEC960803BN control board indicate that the second-stage (high-fire) pressure switch is stuck open. In a two-stage furnace, there are separate pressure switches for low-fire and high-fire operation. This code means the high-fire switch is not closing even though the inducer motor is running.

The second-stage pressure switch requires a higher vacuum level than the first-stage switch because high-fire operation produces more combustion gases that need to be vented. If the inducer motor can generate enough vacuum for first-stage operation but not enough for second stage, the furnace may run on low fire but fail when stepping up to high fire.

Common causes include a faulty second-stage pressure switch, blocked or kinked pressure switch tubing, or an inducer motor that is losing efficiency and cannot produce sufficient vacuum at the higher demand level. Partial vent restrictions can also reduce the inducer's ability to create the stronger draft required for high-fire operation.

Common Causes

When to Call a Professional

Contact a licensed HVAC technician if:

• The furnace cannot operate in second-stage heat and shows 3 double red flashes
• The furnace works on low fire but fails when stepping up to high fire
• The inducer motor sounds weak or labored during high-fire attempts

✓ Verified against manufacturer service manual — March 2026