The Day And Night Furnace Reset Button is a small but critical control used to restart certain furnace models after a safety shutdown. This article explains what the reset button does, how to safely operate it, step-by-step reset and troubleshooting guidance, and when to call a licensed HVAC technician. The content is focused on U.S. households and aims to help homeowners understand risks and remedies without encouraging unsafe DIY repairs.
| Issue | Quick Action | When To Call A Pro |
|---|---|---|
| Temporary Lockout | Press reset after 5–10 minutes cooling | If resets repeat more than twice |
| Ignition Failure | Check power, gas, and reset once | If no ignition after reset |
| Flame Rollout / Overheat | Do Not Reset; shut off and call | Immediately |
What The Day And Night Furnace Reset Button Does
The Day And Night Furnace reset button, sometimes labeled “reset” or “manual reset,” is typically a safety device on older and some current furnaces that requires manual intervention to restart the inducer motor, ignition system, or other controls after a safety fault. It is designed to prevent automatic cycling when a hazardous condition like flame rollout, blocked venting, or repeated ignition failure occurs.
Common Locations And How It Looks
The reset button on Day And Night furnaces is usually located on the control box, blower housing, or near the gas valve. It is often a small, recessed red or black button requiring a fingertip press or a pointed tool. Some models place it behind a service panel; others make it easily accessible on the exterior of the furnace cabinet.
Why Furnaces Require A Manual Reset
Manual resets exist to force the homeowner or technician to inspect the system before restoring operation. This prevents continuous operation in unsafe conditions. A single reset can clear a harmless transient error, but repeated trips indicate a persistent fault needing diagnostic work.
Safety Precautions Before Pressing The Reset Button
Before attempting any furnace reset, turn off power to the furnace at the breaker. Confirm there is no gas smell. If gas is detected, evacuate and call the gas company or 911. Wear safety gloves and eye protection. Avoid repeated resets—limit attempts to two in quick succession.
Step-By-Step How To Reset A Day And Night Furnace
Step 1: Turn Off Power And Gas
Shut off the furnace power at the service switch or main breaker. If accessible and trained, turn the furnace gas valve to the off position. Waiting prevents accidental ignition during inspection.
Step 2: Wait 5–10 Minutes
Allow internal components to cool and any pressure or gas to dissipate. Most manuals recommend a minimum 5-minute wait to clear fault conditions and let control modules reset internally.
Step 3: Inspect Visible Components
Look for obvious issues: blocked vents, disconnected wires, soot or corrosion near burners, or a dirty flame sensor. Check the furnace filter and return air for severe restriction before applying power again.
Step 4: Restore Power And Gas
Turn the breaker back on and open the gas valve. Confirm the thermostat is set to call for heat. If the furnace attempts to ignite, watch for normal operation or immediate safety shutdown.
Step 5: Press The Reset Button Once
Press the reset button firmly once and release. Some models require a full press and hold for one second. If the furnace restarts and operates normally, monitor for a few cycles. Avoid pressing repeatedly if the system fails to start.
Troubleshooting Common Reset-Related Issues
Issue: Furnace Won’t Restart After Reset
If the furnace does not restart, check the thermostat, circuit breaker, and condensate or float switches. A tripped float switch or blocked condensate drain can prevent operation. Also verify the gas supply and pilot (if present).
Issue: Reset Trips Again Immediately
Repeated trips often indicate a persistent safety issue. Common causes include flame rollout, blocked flue, cracked heat exchanger, pressure switch fault, or a malfunctioning inducer motor. Stop attempting resets and schedule professional service.
Issue: Smell Of Gas Or Soot Near Furnace
A gas odor or heavy soot suggests a combustion problem or leak. Avoid using the reset button. Turn off gas and electrical power, ventilate the area from a safe distance, and contact emergency services or the gas company.
When A Reset Button Is Not The Solution
A reset will not fix mechanical failures, clogged burners, cracked heat exchangers, or wiring faults. If the furnace has a history of frequent resets, visible damage, or if safety indicators like flame rollout switches activated, the reset is a temporary measure at best.
How Many Times Is Safe To Reset A Furnace?
Industry guidance generally advises limiting to one or two resets after addressing obvious causes. If a furnace needs more than two resets, it is a strong sign that professional diagnostics and repair are required to ensure safe operation.
Replacing Or Repairing The Reset Switch
If the reset button is physically damaged, sticking, or unresponsive, replacement is reasonable and often inexpensive. Replacement should be done by a qualified HVAC technician or licensed electrician. The button itself is a component on the control board or a discrete switch, and proper wiring and compatibility must be maintained.
Diagnosing Underlying Causes That Trigger Resets
- Blocked Venting Or Flue: Debris, bird nests, or snow can cause dangerous combustion gases to back up.
- Ignition Or Control Board Faults: Failed ignitors, flame sensors, or control boards can cause intermittent lockouts.
- Overheating: Restricted airflow from dirty filters, closed vents, or blower issues can trigger thermal safeties.
- Gas Valve Or Pressure Issues: Low supply pressure or faulty valves prevent proper ignition.
- Cracked Heat Exchanger: Can produce carbon monoxide risk and will trigger safety shutdowns.
Costs And Timeframe For Professional Repair
Service costs vary by region and complexity. Typical diagnostics run $75–$200. Basic repairs like replacing a reset switch or cleaning sensors might cost $100–$400. Major repairs—heat exchanger replacement or gas valve work—can exceed $1,000. Emergency weekend service increases rates.
When To Call For Emergency Service
Call emergency service if there is a strong gas smell, visible flame rollout, suspected carbon monoxide exposure, or if the furnace repeatedly locks out after reset. Those conditions present immediate hazards that require professional response.
Preventive Maintenance To Avoid Reset Trips
Schedule annual furnace inspections and tune-ups before the heating season. Replace air filters every 1–3 months based on use. Keep vents and flue terminations clear of debris and snow. Install carbon monoxide detectors near sleeping areas and the furnace room.
How This Applies To Modern Furnaces And Code Considerations
Many modern furnaces include self-diagnostic controls and electronic lockout features that differ from older manual-reset designs. Local codes and manufacturer instructions define acceptable service procedures. A manual reset should never be bypassed to avoid required safety checks or code compliance.
Useful Resources And Documentation
Refer to the furnace model’s installation and service manual for reset button specifics. Reliable references include the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the U.S. Consumer Product Safety Commission (CPSC), and local utility safety pages. Manufacturer support lines can provide model-specific troubleshooting.
Frequently Asked Questions
Is It Safe To Press The Reset Button After Any Shutdown?
Only if there is no smell of gas and no signs of flame rollout or overheating. Press once after inspection and a brief wait. Repeated resets without fixing the cause are unsafe.
Why Does The Reset Button Keep Popping?
Frequent trips indicate an unresolved issue such as blocked venting, faulty sensors, ignition problems, or overheating. It is not normal and requires professional diagnosis.
Can A Homeowner Replace The Reset Switch?
Technically, yes for simple switches, but replacement should be done by a qualified technician to ensure proper part, wiring, and compliance with safety standards.
Does Resetting Void A Warranty?
Using a reset per the manufacturer’s instructions normally doesn’t void warranty. However, tampering, bypassing safety devices, or nonqualified repairs may affect warranty coverage.
Key Takeaways For Homeowners
Do: Inspect, wait, press reset once, and monitor operation after a safe restart.
Don’t: Repeatedly press reset, ignore gas odors, or attempt major repairs without a licensed technician.
Call A Pro: When resets repeat, when there is evidence of combustion issues, or when safety components like flame rollout switches activate.
| Action | Recommended Response |
|---|---|
| Single reset resolves issue | Monitor; schedule routine maintenance |
| Repeated resets | Call licensed HVAC technician |
| Gas smell or visible soot | Shut off, evacuate, call emergency services |
For safe and reliable heating, the Day And Night furnace reset button should be treated as a warning indicator rather than a permanent fix. Proper inspection and professional service protect both equipment and household safety.