Furnace Stopped Working: What to do?

When the furnace stops working, it can be a cause for concern, especially during cold weather. However, there are several steps you can take to troubleshoot and potentially resolve the issue before seeking professional help. By following a systematic approach, starting with basic checks and progressing to more advanced troubleshooting, you can increase the chances of identifying and rectifying the problem. This article provides an overview of the steps to take when your furnace stops working, offering practical advice to help you restore heat and comfort to your home.

Signs that your furnace has stopped working

Now that we know why a furnace may stop working, it’s important to be able to recognize the signs that your furnace has stopped working. Some common signs include:

What to do if your furnace has stopped working

If you’ve noticed any of the signs mentioned above, it’s time to take action. Here are the steps you should take if your furnace has stopped working:

Check the thermostat

If the furnace has stopped working, checking the thermostat is the first thing to consider. Here’s what you can do-

Verify the power supply

Verifying the power supply is an essential step when troubleshooting a furnace that has stopped working. Here’s what you can do-

Inspecting the air filter

Inspecting the air filter is an important step when troubleshooting a furnace that has stopped working. Here’s what you can do-

Checking the gas supply

Checking the gas supply can really help to check a furnace that has stopped working. Here’s what you can do-

It’s important to exercise caution when dealing with gas-related issues. If you suspect a gas leak or are unsure about any of the steps involved, prioritize your safety and contact a professional HVAC technician or your gas provider for assistance.

Examining the pilot light

Examining the pilot light is a relevant step if you have an older furnace that relies on a pilot light for ignition. Here’s what you can do-

Remember, newer furnaces typically use electronic ignition systems instead of a pilot light. If you’re unsure about your furnace’s ignition system or uncomfortable working with the pilot light, it’s always recommended to seek the help of a qualified professional.

Inspect the air vents and ducts

Inspecting the air vents and ducts is another important step when troubleshooting a furnace that has stopped working. Here’s what you can do:

Reset the furnace

Resetting the furnace can sometimes resolve minor issues or glitches that may have caused it to stop working. Here’s how you can reset the furnace –

If the furnace still doesn’t start or encounters the same issues after the reset, it’s advisable to contact a professional HVAC technician. They have the expertise to diagnose and address more complex problems with the furnace and can ensure proper repairs are made.


Why would a furnace suddenly stop working?

There could be several reasons for a furnace to suddenly stop working, including issues with the thermostat, power supply, pilot light, gas supply, or a malfunctioning component such as the blower motor or ignition system.

What to do when a furnace stops working?

If your furnace stops working, there are a few troubleshooting steps you can take. Check the thermostat settings, ensure the power supply is functioning, and check if the pilot light is lit. If these basic checks don't resolve the issue, it's advisable to contact a professional HVAC technician for a thorough diagnosis and repair.

How do I reset my furnace?

To reset a furnace, locate the furnace's reset switch or circuit breaker and turn it off for a couple of minutes. Then, switch it back on. Refer to your furnace's manual or consult an HVAC professional for specific instructions on how to reset your particular furnace model.

Is there a reset button on my furnace?

Many modern furnaces have a reset switch or button. It is typically located near the blower motor or on the control panel. However, not all furnaces have a reset button. Consult your furnace's manual or contact an HVAC professional to determine if your furnace model has a reset button.

Can a thermostat cause a furnace to stop working?

Yes, a malfunctioning or improperly calibrated thermostat can cause a furnace to stop working. If the thermostat isn't sending the correct signals to the furnace, it may not turn on or cycle properly. Checking the thermostat settings and ensuring it is functioning correctly is an important troubleshooting step.

What is a common failure for a furnace?

A common failure for a furnace is a faulty igniter or pilot light. If the igniter fails to light the burner or the pilot light goes out, the furnace won't be able to produce heat. Other common failures include issues with the blower motor, gas valve, or control board.

How long is the life expectancy of a furnace thermostat?

The life expectancy of a furnace thermostat can vary depending on the quality, usage, and maintenance. On average, a thermostat can last around 10 to 15 years. However, it's important to monitor its performance and consider replacement if you experience frequent issues or notice reduced functionality.

What are the symptoms of a bad thermostat for a furnace?

Symptoms of a bad thermostat for a furnace can include inaccurate temperature readings, unresponsive controls, failure to start or stop the furnace, or irregular cycling of the heating system. If you suspect a faulty thermostat, it's advisable to have it inspected or replaced by an HVAC professional.

What are the signs of a thermostat not working?

Signs of a thermostat not working properly include temperature inconsistencies, the furnace not turning on or off when it should, frequent cycling of the heating system, or unresponsive controls. If you notice any of these signs, it's recommended to have the thermostat checked or replaced by a professional HVAC technician.