Troubleshooting Common Furnace Problems 

It's always a little stressful to wake up early in the morning and find that the house feels a little too cold. At first, it might not be clear what the problem is, but pretty quickly you identify the culprit: the furnace.



This can be particularly alarming depending on the time of year. If you're in the middle of a deep cold spell, in addition to the stress of a frigid house, a furnace that won't turn on can cause concerns about pipes freezing. If you're in the middle of a snowstorm, you might be alarmed about getting assistance in a timely manner.

Truth is, there are a lot of reasons why your furnace might not be working one morning, and solutions can vary pretty widely. But to help you figure out what might be happening, read on.

What Is a Furnace?

If you're a homeowner, you probably have a good idea of what your furnace does, and how it works. But it's still helpful to recap.

Basically, a furnace heats up air, and then that hot air travels via ducts around your home. The furnace is linked to a temperature sensor somewhere in your home, which knows when to kick on the furnace to regulate the temperature. (Your home may also use a boiler, which works similarly but heats up hot water, which is distributed through the home via radiators or other methods. Other types of home heating systems exist as well, including heat pumps, wood-burning stoves, and more.)

Furnaces are complex: they include many parts, including a thermostat, air ducts, a pilot light, a flame sensor, and more. To further differentiate them, they may run on natural gas, propane, or electricity.

When they're working well, they can keep a house comfortable, with minimal effort on your part. But they can become a concern when something goes wrong.

Why Is the Furnace Off?

If the house is cold and the furnace won't start up, the first thing to do is stay calm. There are a handful of reasons why a furnace won't start, and in some cases, you may be able to figure it out yourself.

Gas Is Off or Tank Is Empty

If your furnace runs on natural gas or propane, it requires a continuous supply to keep operating. One of the first things you should check is whether the gas might be turned off, or a propane tank might be empty. Check the gas valve near the furnace, and double-check that any external tank still has sufficient fuel.

Ducts Are Blocked

If air ducts are blocked, your furnace might work but will not be able to distribute heat around the house. Check if air ducts are open if you can; if you're not sure how to, or this feels unsafe to do, call a professional.

Air Filter Is Dirty

The air filter is a critical component in the furnace, but can get clogged with dust and dirt. This will cause some furnaces to shut off. Locate your furnace's air filter, and pull it out to check it. If it looks dirty, replace it.

Thermostat Has a Problem

Sometimes a furnace doesn't work because of an electrical or sensor-related issue with the thermostat. Sometimes this will be obvious, and your thermostat will display an error message. If you're not sure, though, it's probably best to ask an electrician or technician.

Other Problems

Unfortunately, there are a few other problems that can arise with furnaces: a dirty flame sensor, a tripped safety float or high-limit switch, or a blower motor problem. These and other problems can sometimes be trickier for non-professionals to diagnose.

Get the Help You Need

Sometimes identifying the problem with a furnace is easy, even for a non-professional. You may be able to quickly find the issue and fix it yourself, and rapidly get the heat back on.

Sometimes, though, it's important to call a professional. A cold house can be a real problem, and in some cases, it's critical to expedite the repair process. In other cases, trying to identify and fix the problem yourself may feel dangerous. In such cases, it's a good idea to call an expert.

Next Level HVAC is an HVAC Contractor in Santa Rosa that serves Marin and Sonoma Counties for all furnace-related needs. We can help troubleshoot problems, perform regular service, and even install new furnaces. For more information, visit us online or call (707) 228-9921.