Before cranking up your heat for the winter, you should check to make sure your furnace is in good condition.An annual check-up should prevent problems such as…well…not heating your home very well (or at all), or worse – pumping deadly carbon monoxide into your home! Follow these simple furnace maintenance steps to stay safe – and warm – over this winter.Start off by making sure to switch off the electrical power and the fuel supply. This should be done before performing any maintenance. The switch will be red and can usually be found at the top of the cellar or near the burner itself.Next, clean the combustion chamber by removing the cover to access the chamber. Inside this chamber, fuel mixes with air and is ignited, generating heat – as well as carbon soot, water vapor, carbon dioxide, or worse. It’s best to clean the chamber with a small wire brush to scrape out the built-up carbon. Then, use a vacuum to remove loose material, and inspect the chamber for holes or corrosion before replacing the cover. We strongly recommend that during this step you wear safety glasses, a facial mask and gloves. Soot can be very unhealthy and we wouldn’t want you to get any into your system.You should now inspect the flue pipe for holes. (A flue is a pipe, duct, or opening that removes exhaust gases from the combustion chamber to the outdoors.) Look for any gaps, cracks, or small holes could leak carbon monoxide into your home, especially where the pipe meets the furnace. These small holes can be patched with foil tape, but corroded flues must be replaced. While checking your flue, you can also adjust the flue pipe’s damper, which keeps the air moving to help exhaust gases up the flue. Chimneys that are big and tall in old homes tend to suck too much air, compromising heating efficiency.This next step is for oil-powered systems only: It’s important to replace the oil filter in order to prevent small impurities from entering the burner and clogging the oil-burner nozzle, which could result in a misfire that shuts down the system. First, close the oil valve, then remove the old filter and replace it. Disposing of the old filter should be done according to your local hazardous-waste regulations.You will also want to change the air filter in your furnace, which should be replaced every 2-3 months. During this time you can also check the blower belt’s wear and tension. The blower, driven by an electric motor, moves heated air from the furnace through ductwork to room vents. A loose belt can slow the blower, compromising efficiency. If the belt deflects more than ¾ inch when pressed firmly, it can be adjusted by sliding the motor backward slightly.The next step is to adjust the burner and test efficiency by setting up a combustion analyzer, which calculates furnace efficiency by measuring gasses in the exhaust flue. Make sure that the burner’s air gates are adjusted for the proper ration of fuel to air. You can also replace the oil nozzle, which atomizes the oil just before it ignites, and checks the flame color and shape at the igniter. For either oil or gas, this is a key indicator of stable and complete combustion. If you own a gas system, then you should vacuum the burner tubes and make sure they are clean.The last step is to clean the floor vents throughout your home. This time of year is the best time to remove floor registers and vacuum out the ducts. Floor registers and ducts tend to accumulate a lot of dust, pet hair, and food scraps over time. Making sure you clean out these spots will also help you and your family breathe a little easier without all the debris in the air.Now that you have checked your furnace and addressed any issues, you are now ready for the cold weather! Go ahead and turn on the heat and enjoy a safe, warm, and cozy home for the upcoming holiday season. If you run into any issues while checking your furnace, please call your service professional for additional help.