Tempstar Furnace Reset Button: How to Locate, Use, and Troubleshoot

The Tempstar furnace reset button is a simple control used to restart a furnace after a lockout or error. This article explains where to find the reset button, when to use it, step-by-step reset procedures, safety precautions, common causes of lockouts, diagnostic tips, and when to call a professional. The guidance applies broadly to residential Tempstar gas furnaces and compatible HVAC systems.

Topic	Quick Fact
Typical Location	Near the burner assembly or on the control panel behind the access panel
When To Reset	After a safety lockout or ignition failure, only once per incident
Reset Method	Press and hold 5–10 seconds, wait 30 seconds to 1 minute, then restart power
Safety	Turn off power and gas if smells of gas or multiple resets fail

What The Tempstar Furnace Reset Button Does

The reset button is a manual override intended to clear certain system faults, typically ignition failure, flame rollout, or other safety lockouts. Pressing it instructs the furnace control to restart the ignition sequence after an error has been resolved or after the system has timed out. It is not a long-term fix; repeated use indicates an underlying problem.

Where To Find The Reset Button

Location varies by model, but common places include the control compartment behind the front service panel, near the burner box, or on the furnace control board. Some models use a reset switch integrated into an external gas valve or as part of the flame rollout switch assembly.

If the reset button is not visible, consult the furnace’s user manual or the label inside the access panel. The control board often has a small red or black pushbutton labeled RESET or LIMIT RESET.

When It Is Safe To Press The Reset Button

Only press the reset button after checking for obvious hazards. If the furnace smelled strongly of gas or if there is physical damage, do not reset; instead evacuate and call the gas company or emergency services. Safe conditions for a reset include a single ignition failure or brief power interruption with no gas odors.

Step-By-Step Reset Procedure

Tools And Preparations

• Work gloves and eye protection
• A flashlight
• Owner’s manual or model number for reference

Reset Steps

1. Turn Thermostat Off: Set the thermostat to OFF to stop calls for heat.
2. Turn Power Off: Switch off furnace power at the service switch or the breaker to ensure safe access.
3. Access The Reset Button: Remove the front access panel. Locate the reset button on the control board, burner compartment, or gas valve
4. Inspect For Obvious Issues: Look for burned wires, loose connections, debris, or water near the burners. Check the condensate drain if the system is condensing type.
5. Press The Reset Button: Firmly press and hold the reset button for 5–10 seconds, then release. Do not press repeatedly in quick succession.
6. Wait 30–60 Seconds: Allow the control board to complete its restart cycle and clear any residual conditions.
7. Restore Power And Thermostat: Turn the breaker or switch back on and set the thermostat to a temperature above room level to call for heat.
8. Observe The Furnace: Watch the ignition sequence and burner operation for proper firing. If the furnace restarts and runs normally, monitor it for a few cycles.

Common Reasons The Reset Button Is Needed

Ignition problems and safety trips cause most resets. Typical triggers include faulty ignitors, weak or inconsistent gas supply, flame sensor contamination, blocked exhaust vents, and limit switch trips from overheating. Moisture or a clogged condensate drain in high-efficiency units can also trigger lockouts.

How Many Times Can The Reset Button Be Pressed?

Most manufacturers and HVAC professionals recommend pressing the reset button only once per incident. Repeated resets can further damage components and mask serious issues. If the furnace does not restart after one reset, power it down and contact a technician.

Diagnostics After A Reset Fails

If the furnace fails to restart or trips again, follow a systematic diagnostic approach to isolate the cause.

Check For Error Codes

Many Tempstar control boards display LED error codes indicating ignition failure, flame loss, pressure switch issues, or limit trips. Compare the LED flash pattern to the furnace manual to identify the fault.

Inspect Ignition Components

Check the hot surface ignitor for cracks or discoloration. Test continuity with a multimeter if comfortable. A failing ignitor often causes repeated ignition attempts and lockouts.

Examine Flame Sensor

A dirty flame sensor prevents detection of the burner flame, causing shutdown. Remove the sensor and clean gently with fine emery cloth or steel wool, then reinstall securely.

Check Gas Supply And Valve

Confirm that gas is present at the meter and the furnace gas valve is open. If other gas appliances have low performance, contact the gas utility. Do not attempt internal gas valve repairs without certification.

Inspect Venting And Pressure Switch

Obstructed exhaust or intake vents and a failed pressure switch can prevent the furnace from starting. Ensure intake/exhaust terminations are clear of debris, snow, or bird nests. Test pressure tubing for blockages or cracks.

Safety Precautions And Best Practices

• Do Not Reset If You Smell Gas: Evacuate, ventilate, and call the gas company or emergency services before returning.
• Limit Resets: One reset per event; repeated pressing can damage components and hide faults.
• Power Down For Service: Always cut electrical power before accessing wiring or components.
• Follow Manufacturer Guidance: Use the Tempstar manual for model-specific instructions and error code interpretation.
• Use Qualified Technicians: Gas valve, combustion, and control board repairs should be performed by licensed HVAC professionals.

When To Call A Professional

Contact a licensed HVAC technician if the furnace: continues to lock out after a single reset, produces unusual noises, smells of gas, shows water leakage, displays persistent error codes, or if any component appears physically damaged. Technicians can perform combustion analysis, gas pressure testing, control board diagnostics, and safe component replacement.

Replacing Or Servicing The Reset Switch

Reset switches can fail from wear, heat damage, or corrosion. If the switch is sticky, cracked, or does not respond, replacement may be necessary. A professional can source the correct Tempstar part or an OEM equivalent and install it safely.

Preventive Maintenance To Reduce Lockouts

Regular maintenance minimizes the need for resets. Key tasks include annual HVAC tune-ups, cleaning or replacing air filters every 1–3 months, clearing vents, checking condensate lines on high-efficiency units, and testing electrical connections and safety switches.

Model Variations And Control Differences

Tempstar furnaces use different control boards and safety devices depending on model and efficiency rating. Older units may have a visible manual reset limit switch, while newer condensing models rely on electronic control boards with LED diagnostics. Always reference the model number on the furnace rating plate for accurate documentation.

Frequently Asked Questions

Is The Reset Button The Same As The Limit Switch?

No. The reset button can be located on a separate safety device or control panel. The limit switch shuts the furnace off when temperatures exceed safe levels; some limit switches are manual-reset and may be labeled separately.

What If The Furnace Runs For A While Then Shuts Off?

Intermittent operation often indicates flame sensor issues, airflow restrictions, or overheating due to restricted return air or dirty filters. Cleaning the flame sensor and restoring airflow often resolves the problem.

Can A Homeowner Replace The Reset Button?

Homeowners can replace an exposed reset switch if they are comfortable with basic electrical safety and wiring. For gas valve or control board related switches, hiring an HVAC technician is recommended to ensure correct part selection and safe installation.

Does Resetting Affect Warranties?

Using the reset button does not void warranties. However, evidence of improper repair or repeated resets masking a defect could affect warranty claims. Always keep service records for warranty support.

Helpful Resources And Manuals

Tempstar owner manuals and technical bulletins are available from the manufacturer’s website and authorized dealers. The furnace data plate on the unit provides the model and serial number required to find the correct documentation. For wiring diagrams and LED code charts, consult the specific model manual.

Key Takeaways

• Use The Reset Button Only Once Per Incident: Repeated resets signal a deeper issue.
• Safety First: Do not reset if there is a gas odor or visible damage.
• Perform Basic Inspections: Check filters, vents, flame sensor, and ignitor before resetting.
• Call A Professional: Persistent failures, gas-related concerns, or component replacements require licensed technicians.