There is nothing more disconcerting than finding that nothing happens when you turn on your gas furnace. Most of us are familiar with the sounds made by our furnace when we turn it on, so when these sounds don’t happen, it’s a good indication that there is a problem. Unfortunately, these issues rarely occur at a convenient time, so it is important to understand some basic reasons why your furnace won’t run. In many cases, a little troubleshooting will allow you to fix the issue and get your heating restored. So, here are three common reasons why your furnace may not be running and how you could resolve the problem.


When hot air is trapped in your furnace due to some form of blockage, damage can be caused to interior components. Overheating can also occur because of damaged or worn parts. In these types of scenarios, the furnace will shut down to prevent any further damage. If you suspect that your furnace isn’t working because it overheated, check that you’ve closed less than 20 percent of your vents and that your filters are not dirty. If you check the filters and find that they need cleaning or replacing, your furnace may have a reset button that needs to be pressed to restore functionality.

Electrical Issues

Although your furnace is gas fed, it still needs electricity, and if a problem occurs with the electrical feed, the whole system may shut down. Whether this is a surge or an external factor, the breakers for your furnace may have been tripped and need resetting to correct the problem. Ensure that power is being supplied to your furnace and if there is no issue with the power supply, there could be an issue with the ignition or another internal component that will need attention from a trained technician.

Gas Leaks

A gas leak is highly dangerous for both your family and home. For this reason, most furnace models are designed to refuse to switch on if a presence of gas has been detected. Utility companies add an odor to natural gas to aid in detecting a leak, but even if you can’t smell a leak, it is important to err on the side of caution and have your system checked. Even a small leak can be a serious problem for your home and put your family at risk. If you suspect a gas leak, you should avoid using any electrical items that can create a spark, even turning on light switches and contact your utility company or HVAC technician immediately. An experienced repair technician will assess your system and check for any leaks to ensure that your furnace is safe to use.

If you are struggling to determine why your furnace won’t run, it is a good idea to call in a professional HVAC technician, who can check your system and diagnose any underlying issues. An experienced technician has the skills and expertise to quickly resolve any issues and ensure that you’re not left in the cold for long.