My Furnace Won’t Fire Up: Troubleshooting Tips For 2023

My Furnace Won't Turn Off, What Now? [2022] Phyxter Home Services
My Furnace Won't Turn Off, What Now? [2022] Phyxter Home Services from


As the temperature drops, a malfunctioning furnace can quickly turn your home into an uncomfortable and chilly space. If you find yourself in a situation where your furnace won’t fire up, it’s crucial to troubleshoot the issue and get it fixed promptly. In this article, we will discuss some common reasons why your furnace may not be firing up and provide you with troubleshooting tips to help you resolve the problem in 2023.

1. Check the Thermostat

Start by checking your thermostat to ensure it is set to the desired temperature and in the “heat” mode. Make sure the batteries are fresh and correctly inserted. If you have a programmable thermostat, double-check the schedule settings to rule out any programming errors.

2. Inspect the Power Supply

Next, verify that your furnace is receiving power. Check the circuit breaker or fuse box to ensure that the circuit supplying power to the furnace is not tripped or blown. If it is, reset the breaker or replace the fuse. Additionally, check the power switch located on or near the furnace and make sure it is turned on.

3. Examine the Gas Supply

If your furnace runs on natural gas or propane, ensure that the gas supply is not interrupted. Check the gas valve to ensure it is open. If you suspect a gas leak, immediately evacuate your home and contact your gas provider or emergency services.

4. Replace the Air Filter

A clogged air filter can restrict airflow to the furnace, causing it to overheat and shut down as a safety measure. Check and replace the air filter if it appears dirty or clogged. Regularly changing the air filter is essential for optimal furnace performance and longevity.

5. Inspect the Ignition System

Modern furnaces use various ignition systems, such as hot surface ignition or intermittent pilot, to light the burners. If the ignition system is faulty, the furnace won’t fire up. Inspect the ignition system for any visible signs of damage or wear. Consult the furnace’s manual or contact a professional if you are unsure how to proceed.

6. Verify the Pressure Switch

Furnaces are equipped with a pressure switch that ensures proper ventilation and prevents the furnace from firing up if there is an issue. Check the pressure switch for any blockages or malfunctions. Gently clean any debris and ensure the tubing is connected correctly.

7. Check the Flame Sensor

A dirty or faulty flame sensor can prevent the furnace from igniting. Locate the flame sensor, typically positioned near the burners, and clean it using a soft cloth. If cleaning doesn’t resolve the issue, the flame sensor may need replacement.

8. Inspect the Pilot Light

If you have an older furnace with a standing pilot light, ensure that it is lit. Follow the manufacturer’s instructions on relighting the pilot light. If the pilot light won’t stay lit or continues to go out, it may indicate a more significant problem that requires professional assistance.

9. Clear Venting Obstructions

Blocked vents and air intake pipes can disrupt the furnace’s operation. Check the venting system for any obstructions, such as debris, ice, or bird nests. Clear any blockages and ensure proper airflow for the furnace.

10. Call a Professional

If you have gone through the troubleshooting steps above and your furnace still won’t fire up, it’s time to call a professional HVAC technician. They have the expertise and equipment to diagnose and repair complex furnace issues safely.


Dealing with a furnace that won’t fire up can be frustrating, especially during the colder months. By following the troubleshooting tips outlined in this article, you can potentially resolve the issue and restore warmth to your home. Remember to prioritize safety and seek professional help when needed. Stay warm!