Goodman Furnace Starts Then Stops: Causes, Diagnostics, and Fixes

The following guide explains why a Goodman furnace starts then stops (short cycles), how to diagnose common causes, and recommended repairs and maintenance to restore reliable heating. This article covers safety, troubleshooting steps, likely components at fault, estimated repair costs, and when to call a licensed HVAC technician.

Symptom	Likely Cause	Quick Action
Furnace Starts Then Stops After A Minute	Flame Sensor, Dirty Filter, Or Overheat Limit	Clean Flame Sensor, Change Filter, Check Vents
Starts Then Stops Repeatedly (Short Cycling)	Thermostat Or Control Board Fault, Pressure Switch, Inducer Motor	Verify Thermostat Settings, Inspect Venting, Call Professional
Ignition Clicks But No Flame Or Shutdown	Gas Valve Or Ignition Control Problem	Check Gas Supply, Call HVAC Tech

What Is Short Cycling And Why It Matters

Short cycling occurs when a Goodman furnace runs for only a short time before shutting off, then repeats this pattern. Short cycling wastes energy, increases wear on components, reduces comfort, and can shorten the system’s lifespan. Identifying the root cause quickly prevents expensive damage and unsafe conditions.

Common Causes Of A Goodman Furnace That Starts Then Stops

Dirty Or Clogged Air Filter

A clogged air filter restricts airflow, causing the furnace heat exchanger to overheat and the high-limit switch to shut the burner off. After cooling, the furnace will try to restart, creating short cycles. Regularly replacing filters is one of the simplest and most effective fixes.

Faulty Or Dirty Flame Sensor

The flame sensor confirms burner combustion. If dirty or failing, the control board may shut down the gas valve after detecting a perceived flame failure. Symptoms include the furnace starting and then shutting off a few seconds after ignition. Cleaning the flame sensor often resolves the issue.

Thermostat Problems

A miscalibrated, incorrectly wired, or failing thermostat can send rapid on/off signals to the furnace. Incorrect placement (near heat sources) also causes premature shutoff. Verifying thermostat settings and batteries can rule out this common cause.

Blocked Or Improper Venting

Blocked flue pipes, chimneys, or exhaust venting cause combustion or pressure issues that trigger safety switches and shut the furnace down. Mechanical draft interruptions can also cause the inducer motor and pressure switch to shut down the burner sequence.

Pressure Switch Or Inducer Motor Failure

The inducer motor creates proper venting pressure before ignition; the pressure switch confirms correct draft. If the inducer motor fails or the pressure switch is defective, the furnace may start and then stop during the sequence. These components often require professional diagnosis and replacement.

Overheating Or Limit Switch Activation

The furnace has a limit switch that prevents overheating. Restricted airflow or a failing blower motor causes overheating and limit switch trips. After cooling, the furnace restarts, causing short cycling. Inspect blower operation and air passages for obstructions.

Gas Valve Or Ignition Control Issues

A failing gas valve or ignition module may allow combustion to start briefly then shut down. Electronic control boards that detect irregular flame signals may lock out the system after repeated attempts, leading to repeated starts and stops.

Control Board Or Relay Problems

Faulty relays or a failing control board can send intermittent power to the blower, gas valve, or ignition system. Electronic failures often cause unpredictable cycling behavior and usually need a trained technician for safe replacement.

Step-By-Step Diagnostic Checklist For Homeowners

1. Safety First: Turn off power and gas if working on components, and follow the furnace manual. If unsure, call a technician.
2. Check The Air Filter: Replace with the correct MERV-rated filter if dirty. This is the fastest way to eliminate airflow restrictions.
3. Inspect Vents And Return Grilles: Ensure external vents, flue, and return vents are unobstructed by debris, snow, or nests.
4. Thermostat Check: Replace batteries, confirm heating mode and temperature setpoint, and try a different thermostat location or a basic thermostat to rule out electronics.
5. Observe The Ignition Cycle: Note how long the furnace runs before stopping and record any error codes on the furnace control board (LED blink patterns are diagnostics for Goodman furnaces).
6. Clean The Flame Sensor: Remove and gently clean with fine emery cloth, then reinstall. This often fixes short cycling when the flame signal is the problem.
7. Inspect The Blower Motor And Wheel: Listen for unusual noise and check for tight or seized bearings. A weak blower can cause overheating shutdowns.
8. Check For Error Codes: Consult the Goodman manual for control board LED codes to pinpoint probable faults like pressure switch, limit switch, or inducer errors.

When To Call A Professional HVAC Technician

Homeowners should call a licensed HVAC technician when the issue involves gas components, the inducer motor, pressure switch, gas valve, control board, or when safe troubleshooting steps do not resolve the cycling. Gas and combustion-related repairs require certified technicians for safety and code compliance.

Repair Options, Time, And Estimated Costs

Costs vary by region and system model but the following estimates help set expectations. Labor and part costs fluctuate; always request a written estimate.

Issue	Typical Repair	Estimated Cost (Parts + Labor)
Dirty Filter	Filter Replacement	$10–$60
Dirty Flame Sensor	Clean Or Replace Sensor	$40–$150
Thermostat Fault	Replace Thermostat	$80–$300
Inducer Motor Or Pressure Switch	Replace Motor Or Switch	$200–$600
Blower Motor	Repair Or Replace Motor/Wheel	$250–$900
Control Board Or Gas Valve	Replace Control Board Or Gas Valve	$300–$1,200

Goodman Furnace Safety And Diagnostic Codes

Goodman furnaces use a diagnostics LED to flash error codes that indicate faults (e.g., limit trips, pressure switch open, flame failure). Consult the furnace data plate or manual for exact code meanings before attempting repairs. Recording the code and sequence speeds up diagnostics when a technician arrives.

Maintenance Checklist To Prevent Short Cycling

• Replace filters every 1–3 months depending on use and filter rating.
• Schedule annual professional tune-ups including combustion analysis, heat exchanger inspection, and safety control tests.
• Keep supply and return vents open and clear; vacuum near the furnace and remove debris around outdoor ventilation terminations.
• Inspect and clean the flame sensor and burners during tune-ups.
• Test thermostat operation and replace batteries annually.

Troubleshooting Examples And Expected Outcomes

Example 1: Furnace Runs For 30 Seconds Then Shuts Off

Likely cause: Flame sensor dirty or failing. Action: Turn off power, remove sensor, clean with fine emery paper, reinstall. Outcome: If the sensor was the issue, the furnace runs normally. If not, next suspect is the control board or gas valve.

Example 2: Furnace Runs Briefly, Then Shuts Repeatedly With Inducer Noise

Likely cause: Pressure switch or inducer motor failing. Action: Check for blocked venting and error codes; call technician for pressure switch and inducer motor tests. Outcome: Professional repair usually restores normal cycling and safe operation.

Example 3: Furnace Runs, Overheats, Then Shuts Down After A Few Minutes

Likely cause: Restricted airflow due to dirty filter, closed vents, or failing blower motor. Action: Replace filter, open vents, inspect blower. Outcome: Restored airflow often resolves the overheating trips.

Parts To Have On Hand For Common Fixes

• Replaceable pleated filters (correct size and MERV rating)
• Basic screwdrivers, nut drivers, and a multimeter for voltage checks
• Fine emery cloth for cleaning flame sensor
• Replacement thermostat batteries

Energy And Longevity Considerations

Short cycling increases fuel consumption and operating costs. Addressing root causes early improves efficiency, reduces repair frequency, and extends the furnace lifespan. Regular maintenance delivers the best return on investment for energy savings and reliable heating.

How To Communicate The Problem To A Technician

When contacting an HVAC professional, provide model and serial numbers, describe the start-stop pattern (duration of run and off intervals), list any observed error codes, and note recent maintenance actions. Clear information speeds diagnosis and can reduce diagnostic fees.

Additional Resources And Warranty Considerations

Check the Goodman owner’s manual and warranty terms before replacing major components. Some parts may be covered for a period, and authorized dealers can process warranty claims. Use manufacturer resources or the local dealer network for parts and certified service.

If the furnace starts then stops, the most cost-effective approach is to address simple fixes first—filter replacement and flame sensor cleaning—while documenting behavior and error codes to support professional diagnostics when necessary.