Your furnace is one of the most important appliances in your home for keeping you comfortable. Unfortunately, many homeowners do not think about furnace repair or replacement until there is a problem. Here are five warning signs to look out for so that you are never left in the cold.

Your Heating Bill Has Increased

If your furnace is running efficiently and you are not changing your usage patterns, your heating bill should not vary drastically from month to month. If you notice a sudden spike in your heating bill, it could indicate that a failing component is forcing the motor to work harder to provide the same amount of heat, reducing the furnace's efficiency.

Even if your heating bill has not suddenly increased, you may notice that it has been creeping upward each month. This gradual increase indicates an overall loss of efficiency in your furnace that can occur due to age. This is usually a good sign that the furnace needs to be replaced. A professional HVAC technician can inspect your furnace and find its annual fuel utilization efficiency, which will determine if it is time for the furnace to be replaced.

The Burner Flame Is Yellow

A burner flame that is healthy and getting the right balance of gases will be blue and burn steadily. If you notice that your burner flame is flickering or yellow in color, this is a sign that your furnace could be emitting harmful levels of carbon monoxide. If the burner flame is yellow and your family is experiencing frequent headaches, nausea, disorientation, or flu symptoms, there is a definite risk of carbon monoxide poisoning and you should have the furnace serviced immediately.

Your Furnace Makes Excessive Noise

All furnaces make some amount of noise when they are running, but excessive noise is always a sign of a problem. A furnace that is failing can make all manner of noises depending on the specific part or parts that are failing. This will help a technician to determine what the most likely cause of the problem is when he inspects your furnace, and whether or not it needs to be replaced.

For example, if you hear a harsh, metal-on-metal scraping sound, it often means that the blower wheel has come loose from its shaft and is scraping on the blower casing. Squealing and whining noises are signature sounds made by a slipping blower belt, although they could also be a sign that there are bearings that need to be oiled.

Low Indoor Air Quality

Heating the air in your home is not your furnace's only job. Your HVAC system keeps your air clean by removing dust, dander, mold spores, and other allergens from the air as it is blown into your ductwork. Additionally, your furnace is responsible for humidifying the air that passes through your ducts so that it is not stale and uncomfortable. Poor indoor air quality and frequent allergy or respiratory issues can mean that your furnace is in need of repair.

Your Furnace Is Nearing Its Life Expectancy

Even if you are not noticing any problems with your home's current heating solution, no furnace can last forever. If your furnace was already installed when you moved into your home, you should contact the manufacturer with the model number to determine the age of the unit. The average lifespan of a gas furnace is 15 years, so you should consider replacing the furnace if it is within two to three years of this age to avoid heating problems in the future.

While furnaces require little maintenance, it is a good idea to inspect them at least once a month for these common warning signs. This will help to prevent you from being caught off guard by a failing furnace. For more information, contact a company like HomeSmart From Xcel Energy.