Updated 2026-06-25

Goodman Furnace 3 flashes: What It Means & How to Fix It

Compiled & reviewed by Nikolai Tsyrenov · Updated 2026-06-25 · confidence: high

What does Goodman furnace 3 flashes mean?

Pressure-switch circuit is open (did not close) when it should be closed. Most often caused by Pressure-switch hose blocked, pinched, disconnected, or connected improperly.

What Goodman furnace 3 flashes means

Pressure-switch circuit is open (did not close) when it should be closed.

Common causes

Homeowner-safe steps to try

  1. Check the outdoor vent and air-intake terminations for blockage (snow, ice, leaves, nests) and clear what you can safely reach
  2. Make sure nothing indoors is blocking the venting near the furnace
  3. Cycle power at the furnace switch to allow a retry
  4. Do NOT open the furnace to inspect hoses, the inducer, or the pressure switch

When to call a licensed HVAC technician

If the basic checks below don't clear the code, the fault recurs, or anything involves the gas valve, burners, flame sensor or wiring, stop and book a licensed HVAC technician. Repairs to the combustion or gas system are not DIY.

⚠️ Safety first. Gas furnaces burn fuel and produce combustion gases. If you ever smell gas (a rotten-egg or sulfur odor), hear hissing, or your carbon-monoxide alarm sounds, do not touch light switches, thermostats, or the furnace — leave the home immediately and call your gas utility's emergency line or 911 from outside. Homeowners should limit themselves to simple, safe steps: setting the thermostat, checking and replacing the air filter, confirming the furnace switch and breaker are on, keeping supply registers and return grilles open, and clearing snow, ice, or debris from outdoor vent and intake terminations. Never bypass, jumper, or reset safety switches (limit, flame-rollout, or pressure switches), never open the gas valve or burner compartment, and never attempt combustion, electrical, or control-board repairs yourself. Error codes point toward a problem but are not a substitute for proper diagnosis — when in doubt, turn the system off and call a licensed HVAC technician. Keep working carbon-monoxide detectors on every level of your home.
When to call a pro: Call a licensed HVAC technician if the code persists after clearing the outdoor vent/intake — inducer, hose, drain, and pressure-switch diagnosis is needed.

Goodman furnace 3 flashes FAQ

What does Goodman furnace 3 flashes mean?
Pressure-switch circuit is open (did not close) when it should be closed.
What causes Goodman furnace 3 flashes?
Common causes: Pressure-switch hose blocked, pinched, disconnected, or connected improperly; Blocked flue and/or inlet air pipe, or improper vent length/elbows/termination; A weak or failing induced-draft (inducer) blower; Blocked condensate drain (on condensing furnaces) or a failed pressure switch.
Can I fix Goodman furnace 3 flashes myself?
You can safely try: Check the outdoor vent and air-intake terminations for blockage (snow, ice, leaves, nests) and clear what you can safely reach; Make sure nothing indoors is blocking the venting near the furnace; Cycle power at the furnace switch to allow a retry; Do NOT open the furnace to inspect hoses, the inducer, or the pressure switch. Call a licensed HVAC technician if the code persists after clearing the outdoor vent/intake — inducer, hose, drain, and pressure-switch diagnosis is needed.

Other Goodman furnace codes

Goodman 1 flashLockout due to too many ignition retries (3) —Goodman 2 flashesPressure-switch circuit is stuck closed at theGoodman 4 flashesPrimary limit circuit (high-limit switch) is oGoodman 5 flashesFlame sensed with no call for heat — the contrGoodman 6 flashesFlame-rollout switch is open — a safety shutdoGoodman 7 flashesLow flame signal — the flame-sense micro-amp sGoodman 8 flashesProblem with the igniter circuit.

All Goodman furnace codes →

Sources: hvacdirect.com · inspectapedia.com. General information for homeowners, not professional advice — confirm against your furnace's manual and a licensed technician.