March 4, 2025
[Video] How to Shut Off a Gas Furnace Safely
As a Denver homeowner, understanding how to shut off and restart your gas furnace properly is essential for maintaining a safe and comfortable home. Whether you’re performing routine maintenance, addressing a suspected gas leak, or preparing for seasonal changes, knowing the correct procedures can prevent potential hazards and ensure your heating system operates efficiently.
The video below outlines the basic steps to find your furnace shut-off switch and ensure that the gas valve is closed correctly. The remaining blog covers why you might need to shut off your furnace, how to identify a gas leak, and when to call a professional.
Why You Should Know How to Shut Off Your Furnace and Gas Valve
Familiarity with your furnace’s shut-off mechanisms allows you to:
- Respond to Emergencies: In case of a gas leak or malfunction, promptly turning off the gas supply can prevent dangerous situations.
- Perform Maintenance Safely: Before cleaning or servicing your furnace, shutting it down ensures your safety and protects the equipment.
- Enhance Energy Efficiency: Turning off the furnace during warmer months can conserve energy and reduce utility bills.
Signs You Have a Furnace Gas Leak
Recognizing the indicators of a gas leak from your furnace is crucial. If you notice any of the following signs, shut off the gas, evacuate your home, and call a professional immediately. Don’t flip light switches or use your phone near a gas leak.
- Persistent Rotten Egg Smell: Natural gas is odorless; however, utilities add mercaptan to give it a distinctive smell for leak detection.
- Hissing Sounds: A hissing noise near the furnace suggests gas escaping from a leak.
- Physical Symptoms: Exposure to gas leaks can cause headaches, dizziness, nausea, and breathing difficulties.
- Dying Houseplants: Gas leaks can affect indoor plants, causing them to wither or die.
How to Shut Off a Gas Furnace
Follow these steps to shut off your gas furnace safely:
- Turn Off the Thermostat: Set your thermostat to the “off” position to stop the furnace from initiating.
- Locate the Furnace Power Switch: This switch resembles a regular light switch and is typically found near or on the side of the furnace. Flip it to the “off” position to cut electrical power.
- Shut Off the Gas Supply: Locate the gas shut-off valve on the gas pipe leading to the furnace. Turn the valve a quarter turn so that it is perpendicular to the pipe, indicating the gas supply is off.
How to Restart a Gas Furnace
These steps typically activate most modern furnaces. Consult your owner’s manual for steps specific to your model.
- Ensure All Vents Are Open: Confirm that air vents and registers are unobstructed.
- Turn On the Gas Supply: Rotate the gas shut-off valve back to its original position, parallel to the gas pipe.
- Restore Power: Flip the furnace power switch to the “on” position.
- Set the Thermostat: Adjust your thermostat to the desired temperature setting.
If the furnace does not start or you notice any irregularities, it’s advisable to seek professional assistance. Frequently turning your furnace off and on can sometimes create issues that prevent it from starting again.
When to Call an HVAC Professional
Certain situations require the expertise of a licensed HVAC technician:
- Persistent Gas Odors: Continuous smell of gas after shutting off the supply.
- Unresolved Issues: If the furnace fails to restart or operates abnormally.
- Regular Maintenance: Annual inspections and tune-ups ensure optimal performance and safety.
- Carbon monoxide leaks: All homes should have carbon monoxide detectors. If yours goes off, have a professional inspect the source of the problem.
Attempting to repair complex furnace issues without proper knowledge can be hazardous. Professional technicians have the training and tools to address such problems safely.
Get Fast Furnace Maintenance Today
For residents in the Denver area, Applewood Plumbing Heating & Electric offers professional HVAC services to ensure your home’s heating system operates safely and efficiently. Our licensed technicians can assist with maintenance, repairs, and any concerns, including furnace gas leak repair.
For more information or to schedule a service appointment, call the Applewood team today or schedule your service online.