Goodman Furnace Keeps Shutting Off: Causes, Troubleshooting, and Solutions

The following article explains why a Goodman furnace keeps shutting off, outlining common causes, step-by-step troubleshooting, safety considerations, repair options, and estimated costs. It helps homeowners diagnose persistent shutdowns and decide when professional HVAC service is needed. Quick Tip: Many recurring shutdowns are linked to airflow, ignition, or safety switch issues.

Issue	Likely Cause	DIY Fix Possible
Short Cycles	Thermostat, overheating, airflow	Yes
Unit Shuts Off Mid-Heat	Flame failure, pressure switch, limit switch	No/Maybe
Blower Runs But Burner Off	Ignition or control board	Maybe

How Goodman Furnaces Normally Operate

A Goodman furnace follows a sequence: thermostat calls for heat, inducer motor starts, pressure switch verifies draft, ignition lights the burner, main burner runs and heat exchanger heats, blower circulates warm air, thermostat satisfied and cycle ends. Safety components such as the limit switch, pressure switch, and flame sensor monitor conditions and will shut the furnace off if they detect abnormal operation.

Common Causes Of A Goodman Furnace Shutting Off

1. Restricted Airflow And Overheating

Dirty or clogged air filters, closed or blocked supply/return vents, dirty blower wheel, or a blocked return can cause the furnace to overheat. When the heat exchanger temperature exceeds safe limits, the high-limit switch opens and shuts the burners off until cooling occurs.

2. Faulty Limit Switch

The limit switch is a safety device that shuts the burners off when temperatures climb too high. A failing limit switch may trip prematurely or intermittently, causing the furnace to shut off even with adequate airflow.

3. Pressure Switch Or Venting Problems

Inducer and pressure switches ensure proper flue drafting. Blocked venting, a weak inducer motor, or a failed pressure switch can prevent proper draft verification, resulting in shutdowns to prevent combustion gases from entering the home.

4. Flame Sensor Or Ignition Issues

A dirty or failing flame sensor, faulty hot-surface ignitor, or intermittent spark/ignition can cause the furnace to light briefly then shut off when the control board doesn’t detect a stable flame.

5. Thermostat Problems

Incorrect thermostat wiring, shorted thermostat, or placement near heat sources can create false calls for heat or drop calls mid-cycle, causing the furnace to start and stop unexpectedly.

6. Control Board Or Relay Failures

The main control board coordinates ignition, blower, and safeties. Intermittent board failures, bad relays, or corrosion can cause unpredictable shutdowns or failure to maintain burners on.

7. Gas Supply Issues

Low gas pressure, a partially closed gas valve, or interruptions in gas service can cause the burners to shut off after ignition or prevent steady operation.

8. Blocked Condensate Drain (High-Efficiency Models)

For condensing Goodman furnaces, a blocked condensate drain or clogged trap can trigger a safety switch and shut the furnace down to prevent water damage.

Immediate Safety Checks Before Troubleshooting

Turn off the furnace power at the switch or circuit breaker before inspecting internal components. If gas smell is detected, evacuate the home and call the gas company. Ensure the condenser and vent terminations outside are clear of debris. Never bypass safety switches.

Step-By-Step Troubleshooting Guide

Tools And Prep

Tools: screwdriver set, multimeter, replacement air filter, flashlight, soft brush, vacuum with narrow nozzle, and safety gloves. Turn power off and allow components to cool before touching the furnace interior.

1. Check And Replace The Air Filter

Inspect the air filter for dirt and restriction. Replace a dirty filter with the correct MERV rating for the system. A clogged filter is a common cause of short cycling and overheating.

2. Inspect Vents And Registers

Ensure supply and return registers are open and not blocked by furniture or curtains. Check the exterior vent and flue for animals, nests, or debris preventing airflow.

3. Observe The Furnace Operation

With the thermostat set to call for heat, watch the sequence: inducer runs, burners ignite, blower starts. If the furnace shuts off at a specific step, note the behavior and any error lights or codes on the control board.

4. Check Error Codes And LED Indicators

Most Goodman furnaces display diagnostic LED codes. Document the flash code pattern and consult the furnace manual for interpretation. These codes point directly to the failing component or safety trip.

5. Test The Flame Sensor

Turn power off, remove the flame sensor, gently clean it with fine emery cloth to remove buildup, and reinstall. A dirty flame sensor will often cause burners to light briefly then shut down.

6. Inspect The Ignitor And Burners

For hot-surface ignition, look for cracks or erosion. For pilot or spark systems, ensure consistent ignition. Clean burners and remove rust or debris that could disrupt flame stability.

7. Check The Pressure Switch And Venting

Inspect inducer operation and venting for blockages. With the furnace running, the pressure switch should close when the inducer operates. Use a multimeter to test switch continuity; if it fails, replace it.

8. Test The Limit Switch

Locate the limit switch and test for continuity when the furnace is cold. If the limit opens at normal operating temperatures or shows inconsistent readings, replacement is likely necessary.

9. Verify Thermostat And Wiring

Ensure thermostat is set properly and batteries are fresh. Check terminal connections and wiring for corrosion or loose wires. Swap with a known-good thermostat if needed to rule out device faults.

10. Check Gas Supply And Pressure

Confirm gas valve is fully open and other gas appliances operate normally. A licensed technician should measure manifold pressure; homeowners should not adjust gas regulators.

When To Call A Professional HVAC Technician

Call a licensed HVAC technician if diagnostic codes indicate safety device failure, if gas pressure or gas valve issues are suspected, if the control board appears faulty, if the inducer motor or pressure switch needs replacement, or if troubleshooting steps did not resolve the shutdowns.

Important: Gas-related repairs, control board replacements, and sealed combustion or heat exchanger inspections should be handled by certified professionals.

Typical Repair Costs And Timeframes

Repair	Estimated Cost	Time
Air Filter Replacement	$10–$50	15–30 minutes
Flame Sensor Cleaning/Replace	$75–$200	30–60 minutes
Pressure Switch Replacement	$150–$350	1–2 hours
Limit Switch Replacement	$100–$300	1–2 hours
Ignitor Replacement	$150–$400	1–2 hours
Control Board Replacement	$300–$800	1–3 hours

Costs vary by region, model, and whether additional diagnostics reveal related issues. Emergency or weekend service often adds premium fees.

Preventive Maintenance To Reduce Shutdowns

• Replace air filters every 1–3 months depending on use and pets.
• Schedule annual professional tune-ups before the heating season.
• Keep vents, returns, and exterior flue terminations clear of debris and vegetation.
• Install a programmable or smart thermostat to reduce rapid cycles and uneven operation.
• Ensure adequate clearance around the furnace and maintain a clean furnace cabinet.

When Shutdowns Indicate A Serious Problem

Repeated trips of the limit switch, visible cracks in the heat exchanger, persistent gas odor, or frequent control board resets may indicate severe hazards. A cracked heat exchanger can allow combustion gases, including carbon monoxide, into the home and requires immediate professional evaluation.

How To Use Diagnostic LED Codes On Goodman Furnaces

Goodman furnaces typically use a two-digit or multi-flash LED diagnostic code. The pattern of long and short flashes corresponds to specific faults such as limit open, pressure switch failure, or ignition fault. Document the pattern and consult the model’s manual or the manufacturer’s website for code definitions.

Replacement Versus Repair Considerations

If repair costs exceed 50% of a new furnace price, or the furnace is older than 15–20 years with recurring failures, replacement may be more economical. Consider energy-efficiency improvements with a new high-efficiency model and potential rebates or tax incentives for newer systems.

Key Takeaways For Homeowners

• Airflow Causes Many Shutdowns: Start with filters, vents, and blower cleaning.
• Read Diagnostic Codes: LED flash patterns point to the failing system part.
• Handle Gas And Control Repairs Professionally: Hire licensed technicians for ignition, gas, pressure switch, and control board issues.
• Regular Maintenance Prevents Most Problems: Annual service reduces unexpected shutdowns and extends furnace life.

Resources And Further Reading

Manufacturer manuals and the Goodman support site contain model-specific diagnostic code charts and wiring diagrams. The U.S. Consumer Product Safety Commission and local utility pages provide safety guidelines about CO detectors and furnace ventilation.