Many Comfortmaker furnace models include a reset function to recover from temporary faults that prevent the furnace from starting or operating normally. The reset button, if present, is not a substitute for professional service, especially after persistent shutdowns or gas smells. Understanding where the reset button is, when to use it, and how to perform a safe reset can help homeowners restore operation quickly while avoiding unsafe conditions. This guide explains how the Comfortmaker furnace reset button works, how to locate it, and the proper steps to reset with safety and reliability in mind.

Understanding The Comfortmaker Furnace Reset Button

The Comfortmaker furnace reset button is designed to clear certain fault conditions that block ignition or airflow. It is not a universal remedy for every problem and should be used only after checking basic safety factors such as gas supply, electrical power, and thermostat settings. Some models employ a dedicated reset button on the gas valve or control board, while others rely on cycling power rather than a physical button. Manufacturers emphasize that repeated resets can mask serious issues, including ignition failure or restricted venting. Always consult the owner’s manual for model-specific guidance.

Key point: the reset function serves to restart a faulted control sequence once potential simple causes are addressed. If the unit remains in fault after a reset, or if you detect a gas smell, seek professional service immediately. For most American homes, CO detectors should be mounted near sleeping areas and tested monthly to enhance safety during any furnace operation or reset attempt.

Locating The Reset Button On A Comfortmaker Furnace

Locating the reset button depends on the model and design of the furnace. In many Comfortmaker gas furnaces, the reset button is found on the gas valve near the burner assembly or on the primary control board inside the cabinet behind the access panel. Some models do not have a dedicated reset button; in those cases, the reset is achieved by cycling power to the unit. If a reset button exists, it is usually labeled “Reset” and commonly colored red or yellow for visibility.

Check the burner access panel for a small red or yellow push button labeled “Reset.”
Look on the gas valve body for a small reset button or switch, often near the wiring harness.
On models without a reset button, locate the main power switch or the circuit breaker feeding the furnace for cycling power.
Always refer to the specific model’s user manual, since layouts vary by year and configuration.

When Should You Reset Your Comfortmaker Furnace

A reset is generally appropriate after certain non-emergency fault conditions, but not after every failure. Consider resetting if the furnace has briefly locked out due to ignition timeout, a temporary electrical glitch, or after servicing that requires power cycling. Do not reset if there is a gas odor, if the furnace is making unusual noises, or if the flame is not establishing properly. If a red diagnostic light or fault code appears, consult the manual for the meaning before resetting, as some codes indicate conditions that require professional attention.

Ignition lockout after failed ignition attempts.
Temporary power interruption that caused a fault code.
Flame sensor or main control that has flagged a recoverable fault after inspection.
Thermostat or wiring issues that might be resolved through a power cycle.

Step-By-Step Reset Process For Comfortmaker Furnaces

Ensure safety: If you smell gas, evacuate and call your gas utility or emergency services. Do not operate electrical switches in a gas-leak area.
Turn off power to the furnace: Switch off the unit at the dedicated switch or the circuit breaker. Leave it off for at least 30 seconds to discharge capacitors.
Open the access panel: Remove the panel to reveal the burner and control components. Keep hands clear of moving parts.
Locate the reset button or power-cycle control: If a reset button is present, locate it on the gas valve or control board. If there is no button, proceed with power cycling.
Perform the reset:
- If there is a reset button: Press and hold the button for 3–5 seconds, then release. You may hear a click or see indicator lights change.
- If there is no reset button: Restore power by flipping the circuit breaker back to ON, or switch the furnace power switch to ON after a brief pause.
Restore power and observe: Close the access panel, turn the thermostat to a heat setting, and wait for the furnace to begin its start-up sequence. A typical start involves ignition, burner operation, and blower ramping up after the heat exchanger warms.
Monitor for normal operation: A properly reset furnace should light, run for a few minutes, and reach setpoint without tripping again. If it cycles off early or again trips, do not repeatedly reset; seek professional diagnostic help.

What To Do After Reset And Common Troubleshooting

After a reset, observe the furnace behavior and verify that the system reaches the desired temperature without repeated lockouts. If the unit starts but runs irregularly, troubleshoot common issues such as dirty filters, obstructed intakes, or thermostat calibration. If the flame does not establish or extinguishes quickly, the issue could involve gas supply, gas valve operation, or flame sensor contamination. In such cases, do not push the unit to restart repeatedly; instead, perform a targeted check or contact a licensed HVAC technician.

Symptom	Possible Cause	Recommended Action
Furnace does not start after reset	No power, tripped breaker, or failed ignition	Check power at breaker, inspect wiring, verify gas supply, and review fault codes. If unresolved, call a pro.
Furnace starts but shuts down within minutes	Ignition timeout, flame sensor issue, or restricted venting	Inspect flame sensor, clean if accessible, ensure venting is clear, and verify gas pressure. Seek professional help if problem recurs.
Gas smell or suspect leak	Gas valve issue or leak nearby	Evacuate, call emergency services or gas company. Do not reset or operate switches in a gas-leak area.
Thermostat shows fault after reset	Wiring or communication issue between stat and furnace	Check thermostat wiring, replace batteries if needed, and re-sync thermostat. If codes persist, contact an technician.

Maintenance To Reduce Future Resets

Proactive maintenance minimizes the likelihood of reset-driven interruptions. Regular filter changes help maintain airflow and reduce strain on the furnace. Schedule an annual professional inspection to clean burners, verify flame quality, and test safety controls. Ensure the gas valve and ignition system are free of corrosion and dirt. Keep the area around the furnace clear of dust, debris, and stored items to promote efficient combustion and proper venting. Install and test carbon monoxide detectors per local code and manufacturer recommendations.

Change furnace air filters every 1–3 months, depending on usage and household conditions.
Keep outdoor vents and intake openings free from obstructions.
Calibrate the thermostat to ensure accurate temperature control.
Schedule annual professional service to inspect ignition, flame sensor, and control board integrity.

When To Call A Professional

Call a qualified HVAC technician if resetting does not resolve the issue, if fault codes reappear, or if there is any possibility of a gas leak. Do not attempt complex repairs such as gas valve servicing, flame sensor replacement, or control board diagnostics without proper training. A pro can perform a safe inspection, verify gas pressures, check electrical connections, and ensure venting and CO detectors meet safety standards. Early professional intervention can prevent further damage and maintain system reliability.