5 Reasons your Furnace is Running Constantly

Hey there, homeowner! So, it seems you've been noticing your furnace running non-stop. That's not just annoying; it can also be a real drain on your energy bills. So, let's take a closer look at why your furnace is operating constantly.

1. Your Thermostat is Misbehaving

A leading culprit when it comes to a furnace that runs constantly is often a misbehaving thermostat. The thermostat in your home is the brains behind your heating system. It dictates when your furnace should kick in and when it should take a breather.

If your thermostat is set to a high temperature or is stuck in the 'on' position, your furnace might be taking its orders a bit too seriously and working overtime. It also could be that your thermostat is not correctly reading the temperature in your home. If it thinks it's colder than it actually is, it will keep your furnace running to reach a temperature that's already been met.

So, before you start worrying about your furnace, check your thermostat settings. Try lowering the temperature or switching it to 'auto' if it's currently set to 'on'. If this doesn't solve the problem, you might want to call in a professional to check if your thermostat needs replacing or repairing.

2. Dirty Air Filters

Another common reason why your furnace might be operating constantly is a dirty air filter. Air filters are essential in maintaining good air quality in your home. They trap dust, dirt, and other airborne particles, preventing them from circulating throughout your house.

However, if your air filter gets too dirty or clogged, it can restrict airflow to your furnace. This makes the furnace work harder and longer to heat your home, resulting in a furnace that runs constantly. So, one of the first things you should do when you notice your furnace running all the time is check your air filter. If it's dirty, replace it as soon as possible.

3. Incorrect Furnace Size

Size matters, especially when it comes to your furnace. If your furnace is too small for your home, it will need to work harder and longer to heat your space, leading to constant operation. On the other hand, if it's too large, it will heat your home too quickly, causing it to turn on and off frequently, a phenomenon known as short cycling.

So, how can you tell if you have the wrong-sized furnace? If your furnace has always run constantly since it was installed, it's likely too small. If it's relatively new and you've just started noticing the problem, it could be too large. In either case, it's best to consult with a heating professional to determine the right furnace size for your home.

4. Leaky Ducts

Leaky ducts can also be the reason why your furnace is operating constantly. If the ducts in your home have holes or cracks, hot air can escape before it reaches your living spaces. This means your furnace has to run longer to maintain the desired temperature.

To check for leaky ducts, you can look for signs of dust around your vents or unusually high energy bills. But, again, a professional can provide a more thorough inspection and recommend the best course of action.

5. Lack of Maintenance

Last but not least, a lack of regular maintenance can result in a furnace that runs constantly. Like any machine, your furnace needs regular check-ups to ensure it's running efficiently. Neglecting this maintenance can lead to various problems, including constant operation.

Regular maintenance includes cleaning and replacing air filters, checking and sealing ducts, inspecting and cleaning the blower motor, and more. These tasks not only help keep your furnace running smoothly but also extend its lifespan and can help prevent more serious problems down the line.



In conclusion, if you're asking yourself, "why is my furnace operating constantly," the answer could be any number of things: a misbehaving thermostat, dirty air filters, the wrong furnace size, leaky ducts, or a lack of maintenance. But, by taking the time to pinpoint the issue, you can ensure your furnace is running efficiently and save yourself from costly energy bills. If in doubt, always call in a professional to assess the situation and provide a solution. Happy heating!