Your furnace is an essential component of keeping your home a comfortable place to live. It can only do that if it is functioning properly. While furnace repair is a necessary part of having a unit, some issues may necessitate that you replace your furnace.

How Long Do Furnaces Typically Last?
The lifespan of a furnace depends on a number of factors. Furnaces that don’t have to work as frequently or deal with as many environmental pressures commonly last longer than units that are in constant use. A unit that isn’t a good fit for the home it is in, perhaps because it is too small to heat a big house or doesn’t have the proper ventilation, will also have a shorter lifespan.
Regular maintenance is a good way to preserve the lifespan of a furnace. This includes even simple things like regularly cleaning out the filters or replacing the fan blades as they wear down. As a general rule, furnaces are good for about 15–20 years. Some of the newer highly efficient models may even last up to 30 if they are treated with kit gloves. Because furnaces usually come with a house, it is wise to check when yours was installed pretty early on so you know what to expect.
Knowing When It’s Time to Replace Your Furnace
Knowing when to replace your furnace can be a delicate call since it is no small process or expenditure. However, there are some signs that can help you know the end is in sight. Pay attention to these as they arise so you won’t be left with an emergency replacement situation.
Frequent Maintenance Calls
If you have to call in the professionals on a semi-regular basis, it might be time to have your furnace replaced. Frequently servicing your furnace is both time-consuming and disruptive to your lifestyle. Living on the edge of your seat, not knowing when the furnace will fail again, is no way to live. Replacing your furnace can provide peace of mind, knowing that your home is warmed without a catch.
If you have to call in the HVAC technician several times a year for furnace repairs, it may actually be more cost-efficient to replace your furnace. Carefully weigh the cost of repairs and the mental toll of not knowing when your unit will die against the sticker price of a new furnace.
Higher Energy Bills
An uptick in your energy bill may indicate a furnace that is running less efficiently. Sometimes this can be addressed with maintenance, but it may also mean that you need to replace your furnace.

Uneven Temperatures
When a furnace is on its last legs, it tends to heat the home unevenly. You may even notice that some rooms don’t get heated at all. Check first that the vents are not covered and that your ductwork doesn’t have leaks, but if your furnace is producing cool air, that’s a red flag.
Spitting Out Dust
The air coming from your furnace should be warm and clean. Sometimes, however, when a furnace is old and no filter changes can stop it from expelling dust, dirt, and debris into your home, it’s a warning sign that the unit is on its way out.
Unusually Loud or Quiet
Furnaces have a normal level of sound output, both when they are running and when they are idle. A noisy furnace is not a good sign. Clicking usually indicates that the flame sensor or ignitor is struggling while rattling may mean loose ducts or something worse. Call in a professional to take a peek if your furnace gets too chatty.
Humidity Problems
Sometimes a furnace on its way out may cause humidity issues in a home. If you notice that your furniture or musical instruments are unnaturally dry or that you experience an abnormal number of static shocks, you might need to replace your furnace.
Leaking Carbon Monoxide
Cracks in a furnace’s heat exchanger can allow carbon monoxide to leak into your home. This is a non-negotiable problem as carbon monoxide is highly toxic and fatal if inhaled too much. If you experience nausea or headaches near your furnace, open all the windows immediately and call in the professionals.
Evident Damage
Some damage, like cracks, rust, or corrosion, may not be worth the hassle to repair and subsequent diminished efficiency. If you notice any of these signs on your furnace, start looking for a new one.

A Professional Opinion
As mentioned above, it is important to replace your furnace before the need reaches emergency status. If you are in doubt about any of the signs mentioned above, let a professional assess the situation. A member of our Energy Masters team can look over your unit and offer you an annual fuel utilization efficiency (AFUE) rating. If your unit is performing below optimal levels (around 80% for mid-efficiency furnaces and closer to 90% or high-efficiency units), we can help you decide what needs to be done and if it really is time to replace your furnace.