Your furnace is the only thing that keeps the interior of your home comfortable when the temperature dips below freezing and the snow is blowing against your windowpanes, but just like every other major appliance in your home, your furnace has a finite lifespan. Understanding the warning signs associated with a furnace that is on its last legs can help you identify the issue and replace the unit before your furnace fails in the dead of winter, leaving you shivering and waiting for a replacement.
One of the easiest to notice warning signs associated with a failing furnace is a series of loud and unusual noises coming from your unit when it kicks into gear. Sometimes this can be something as minor as a loose brace for your ductwork allowing some shaking to occur when the fan starts to blow, but other times it can point to a loose belt or unbalanced moving part within your furnace itself. This should be checked out immediately, as it is more than a slight annoyance: loose and shaking parts within your furnace can quickly increase the amount of wear that surrounding parts experience and can speed up a critical failure.
Increased Energy Bills
Another fairly obvious indicator that your furnace is on its way out is if your energy bills have suddenly spiked without a corresponding increase in the amount of usage that you are getting out of your home's major appliances. This is especially true if your unit is several years old: older units will be less energy efficient and will become exponentially more expensive to operate as their interior workings degrade and make the entire unit less efficient.
If you notice that drafts, cold spots, and other indications of uneven heating have begun to crop out within your home where they otherwise did not exist, your furnace's heating elements may be beginning to give out, or another mechanical failure has caused the unit to begin to struggle to heat the area that it otherwise was able to service without an issue. Not only will this reduce your comfort levels within your home, it will likely also lead to increased energy bills, as your furnace works harder and longer to make up for its loss of effectiveness. Of course, if your furnace has already begun to blow cold air, it's a clear sign that the unit has already failed and needs to be entirely replaced.
For more information about heating installation, contact a local professional.