Why My Furnace Keeps Shutting Off and Needs to Be Reset?
A furnace that constantly shuts off and needs resetting can be a major inconvenience when temperatures drop. These interruptions often signal underlying issues that need prompt attention. Ignoring them can lead to decreased heating efficiency, higher energy bills, or even permanent damage to your system.
Understanding the reasons behind these frequent shutdowns is the first step to resolving the issue and ensuring your furnace operates smoothly. In this guide, let’s discuss the common causes of furnace shutdowns and solutions to help restore consistent heating to your home.
Common Reasons Why Furnaces Keeps Shutting Off
Dirty Air Filters
Clogged air filters restrict airflow, causing the furnace to overheat and shut off as a safety measure. Over time, restricted airflow can strain the system, reducing its lifespan.
To prevent this issue, it is recommended that air filters be replaced every 1-3 months, especially during heavy usage periods. Also, check filters regularly and clean them if they are reusable.
Thermostat Issues
A malfunctioning or improperly set thermostat can cause frequent cycling or complete shutdowns. The furnace may shut off prematurely if the thermostat isn’t accurately reading the temperature.
Verify the thermostat is set to “heat” mode and adjust the temperature to a higher setting. Replace the batteries if needed, or consider upgrading to a programmable or smart thermostat for better control.
Blocked or Closed Vents
Blocked or closed vents restrict airflow, which can cause the furnace to overheat and shut down. This often happens when furniture, rugs, or debris obstruct vents.
Inspect all vents and registers to ensure they are open and unobstructed. Rearrange furniture or remove debris to allow proper airflow throughout your home.
Pilot Light or Ignition Problems in Gas Furnaces
A weak or extinguished pilot light or a faulty ignition system prevents the furnace from starting or staying on. This can result from dirt buildup or component wear.
If the pilot light is out, relight it following the manufacturer’s instructions. Clean the ignition assembly or contact a technician to repair or replace the part for ignition systems.
Flame Sensor Issues
A dirty or faulty flame sensor can fail to detect the flame, causing the furnace to shut off for safety reasons. This safety feature prevents gas from accumulating in the system.
To resolve this issue, turn off the furnace and carefully clean the flame sensor with a soft cloth or fine sandpaper. If cleaning doesn’t resolve the issue, replace the sensor or consult an HVAC technician.
Overheating Due to a Faulty Blower Motor
A malfunctioning blower motor can prevent the system from circulating air, causing the furnace to overheat and shut down. The furnace may also exhibit unusual noises or weak airflow.
To tackle this issue, turn off the furnace and inspect the blower for dirt or damage. Call a professional furnace repair company to repair or replace the blower motor if it continues to malfunction.
Faulty Limit Switch
The limit switch monitors the temperature inside the furnace. If it malfunctions, it can incorrectly signal the furnace to shut down.
However, do not attempt to repair the light switch yourself, as it is a sensitive component. If the light switch seems to be the problem, contact a professional for repair and replacement.
Gas Supply or Pressure Issues in Gas Furnaces
Insufficient gas supply or pressure can cause the furnace to shut down unexpectedly. This can occur due to a closed gas valve or issues with the gas line.
Make sure the gas valve is fully open. If the problem persists, contact your gas provider to verify the supply and pressure. For internal gas line issues, call a licensed technician.
Electrical Circuit Problems in Electric Furnaces
Electric furnaces rely on a consistent power supply to function. Electrical issues, such as tripped breakers, blown fuses, or damaged wiring, can disrupt the power supply and cause the furnace to shut off unexpectedly.
If you have an electrical furnace, check your home’s electrical panel to see if the circuit breaker has tripped. Reset the breaker or replace any blown fuses. If the furnace loses power, have an electrician inspect the wiring for damage or faults.
Ventilation or Exhaust Blockages
Blocked exhaust vents, flues, or chimneys can prevent the proper release of combustion gases, triggering safety mechanisms that shut down the furnace. This is common in older systems or homes with poorly maintained venting systems.
Regularly inspect the furnace’s exhaust system for visible blockages, such as debris, bird nests, or snow buildup. Clear any obstructions to restore proper ventilation. For extensive blockages or damage to the exhaust system, hire a professional to clean or repair the venting components.
Prevent Furnace Problems with Regular Maintenance Service
Regular maintenance ensures your furnace stays in optimal condition. You can avoid frequent shutdowns and costly repairs by addressing small issues like dirty filters, blocked vents, or worn-out components early. It also extends the lifespan of your furnace, keeping your home comfortable throughout the season.
If you’re facing persistent furnace issues or need professional assistance, Air Control Services is here to help! Our furnace inspection and repair service in Las Cruces, NM, is designed to diagnose and resolve heating issues promptly and efficiently.
Call (575) 636-2754 to schedule a furnace inspection.
FAQs
Why do I have to reset my furnace every day?
If you need to reset your furnace daily, it could be due to a failing flame sensor, insufficient gas supply, or an ignition problem. These issues often prevent the furnace from maintaining consistent heating.
Why would the furnace stop working and then start again?
Frequent stopping and starting, known as short cycling, is usually caused by clogged filters, thermostat issues, or overheating. Addressing these problems can restore consistent operation.
Will a furnace reset itself?
Most furnaces do not reset themselves automatically. You’ll typically need to manually press the reset button, but frequent resets indicate a persistent issue that requires professional attention.
Why does my furnace keep shutting off within 15 minutes of heating?
This could be caused by an overheating system, often due to blocked vents or a dirty air filter. It may also indicate a malfunctioning thermostat that shuts the furnace off prematurely.