You wake up on a chilly morning, and your Goodman furnace isn’t doing its job. No warm air, maybe a strange sound, or the blower is running nonstop.
Before you panic (or call a pro right away), take a deep breath. Many furnace issues have simple fixes that you can check yourself in minutes. Others will require a licensed HVAC technician.
As Savvy — your eco-conscious, budget-smart homeowner guide — I’ll walk you through step-by-step troubleshooting for when your Goodman furnace isn’t heating right, so you can save time, money, and stress.
🛡 Safety First: Before You Start
Your furnace runs on natural gas, electricity, and high temperatures — all potentially dangerous. Keep these rules in mind:
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🔌 Shut off power at the switch or breaker before opening furnace panels.
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🔥 Check for gas smells. If you smell rotten eggs (sign of a gas leak), leave immediately and call your gas utility — do not attempt DIY troubleshooting.
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❌ Never bypass safety switches. They exist to protect you.
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🏠 Install a carbon monoxide detector. Every home with a gas furnace should have one near sleeping areas.
📖 Energy.gov stresses that safety checks should always come first in furnace troubleshooting.
🔍 Why Your Furnace May Not Be Heating
A Goodman furnace that isn’t heating properly can be caused by:
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Thermostat missettings.
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Clogged or dirty air filters.
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Power issues (switch, breaker, wiring).
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Ignition or pilot light problems.
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Gas supply interruptions.
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Blower or motor malfunctions.
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Faulty sensors or control boards.
Knowing these possibilities helps you start with the most common, easy-to-fix issues before moving to more complex repairs.
🪣 Step 1: Check the Thermostat
The thermostat is often the culprit — and it’s the easiest fix.
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✅ Make sure it’s set to HEAT.
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✅ Set temperature higher than current room temp.
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✅ Replace batteries if it’s battery-powered.
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✅ Ensure the fan setting is on AUTO, not just “ON” (which runs blower without heat).
💡 Savvy’s Tip: “If your thermostat screen is blank, replace batteries first. I’ve seen too many homeowners call for service when it’s just dead batteries.”
🪣 Step 2: Inspect the Air Filter
A dirty filter can:
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Block airflow.
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Cause the furnace to overheat and shut down.
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Reduce efficiency by 10–15%.
Steps:
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Locate your filter (inside return grille or blower compartment).
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Hold it up to light. If you can’t see light through it, replace it.
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Use the correct Goodman-approved size.
📖 ENERGY STAR recommends checking filters monthly, replacing every 1–3 months.
🪣 Step 3: Confirm Power Supply
If your Goodman furnace doesn’t turn on at all:
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Look for a light switch near the furnace — make sure it’s ON.
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Check your breaker box for tripped circuits. Reset if needed.
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Some furnaces have a fuse inside the control board — if blown, a pro must replace it.
💡 Savvy’s Tip: “Don’t overlook the simple stuff. Half the calls HVAC techs get are just flipped switches or tripped breakers.”
🔥 Step 4: Inspect Ignition or Pilot Light
Most modern Goodman 96 AFUE furnaces use electronic ignition instead of a standing pilot.
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Listen for clicking sounds when it tries to start.
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Look for flashing error codes on the control board (see Step 6).
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If your furnace is older with a pilot: make sure the flame is blue and steady. If out, follow Goodman’s manual to relight.
📖 Goodman Support provides ignition and pilot troubleshooting guides.
⛽ Step 5: Verify Gas Supply
If ignition fails repeatedly:
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Ensure the gas valve is in ON position (parallel to the pipe).
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Check other gas appliances (like stove) — if they don’t work, it may be a utility issue.
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Call your gas provider if you suspect a service interruption.
⚠️ If you smell gas: leave immediately and call your gas company.
💡 Step 6: Look for Error Codes
Goodman furnaces are designed to help you troubleshoot.
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Look for the LED light inside the control panel.
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Count the flashes — they correspond to diagnostic codes.
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Common codes include:
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1 blink = ignition failure.
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3 blinks = pressure switch problem.
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6 blinks = rollout switch tripped.
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💡 Savvy’s Tip: “Snap a photo of the error code flashing before calling a tech — it speeds up diagnosis and saves labor costs.”
🔊 Step 7: Listen for Unusual Noises
Furnace sounds can be clues:
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Banging = delayed ignition or duct expansion.
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Grinding/Squealing = blower motor bearing issues.
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Whistling = clogged filter or duct leaks.
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Clicking = ignition system misfiring.
📖 Consumer Reports notes that noises often indicate mechanical issues needing professional service.
🛠 When to Call a Pro
After checking thermostat, filter, power, gas, and codes — if your Goodman furnace still won’t heat:
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Burner won’t ignite after reset attempts.
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Blower runs constantly.
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Furnace cycles on/off rapidly (short cycling).
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Strange smells (burning or gas).
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Carbon monoxide detector alarm goes off.
💰 Potential Repair Costs
Here’s what common fixes may cost in 2025:
| Repair | Typical Cost |
|---|---|
| Filter replacement | $10–$40 |
| Thermostat replacement | $150–$400 |
| Igniter replacement | $150–$300 |
| Flame sensor replacement | $100–$250 |
| Blower motor repair/replacement | $500–$1,500 |
| Control board replacement | $400–$800 |
| Heat exchanger replacement | $1,000–$2,000 |
| Full furnace replacement | $3,500–$6,500 |
📖 HomeAdvisor provides updated repair cost ranges.
🌱 Savvy’s Troubleshooting Hacks
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“Always start with the thermostat and filter — they solve 50% of heating issues.”
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“Error codes are your friend — snap a photo to show your HVAC tech.”
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“If your blower runs nonstop, check that your thermostat fan is set to AUTO.”
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“Regular maintenance (filter + annual tune-up) prevents most breakdowns.”
🔭 Final Word from Savvy
A Goodman furnace that isn’t heating right doesn’t always mean disaster. In many cases, it’s something simple: thermostat settings, a dirty filter, or a tripped breaker.
But when it’s not simple, knowing what to check first saves time, helps your HVAC tech diagnose faster, and protects your wallet.
