Electric furnaces last between 20-30 years. Gas furnaces typically have a lifespan of 15-20 years. If youโve kept up with the regular maintenance then itโs not unheard of to get a solid 20 years from your gas furnace. The trick is to be able to gauge its performance and recognize the warning signs that itโs time to replace your furnace.
At City Energy, we guide our customers on how to make the best decision when it comes to deciding between repair and replacement. Replacement is probably not the right solution if your furnace is relatively new. Sometimes a simple repair is all you need to keep your furnace running in tip-top shape. However, if youโre experiencing any of the following issues with your furnace, we consider these signs that it needs replacement.
Thereโs evidence of soot build-up
This is one of the more urgent signs that itโs time to replace your furnace. If you notice soot building up around your furnace or the air registers then itโs time to call a professional HVAC contractor. Soot is usually an indication that something is blocked or your furnace is not burning efficiently.

If your furnace is in the last stages of its life it could be producing excessive carbon monoxide. In most cases, it takes a while to build up and isnโt an immediate threat. There are, however, enough horror stories to be concerned with the performance of your furnace. In rare situations, it could present a threat to the quality of the air youโre breathing since carbon monoxide is a toxic gas that can kill in high concentrations.
Keep in mind that a dirty furnace and air ducts can also lead to coughing and a dry and irritated throat. You may be able to avoid replacing a furnace by simply cleaning the ducts, replacing the filters and cleaning your furnace.
My furnace is making noises
Noises are a common occurrence, as a furnace gets older. If you hear the following sounds be sure to call us and schedule an appointment. Not all sounds indicate itโs time to replace your furnace. Sometimes a simple furnace repair is all thatโs needed depending on the age of your unit.
Rumbling
If your furnace is rumbling after it has already gone through a heating cycle, it could mean that itโs continuing to burn fuel in the combustion chamber. This presents a need for a professional to take a look and identify the problem.
Loud and sudden pop or bang
Dirty furnace burners or damaged air ducts are the most likely culprits when you hear a loud popping coming from your furnace. If dirt builds up on the burners they donโt ignite right away and gas builds up. When it finally ignites thatโs the loud popping-sort of a mini-explosion!
This can become a serious issue since the explosions can become bigger and damage the heating systemโs components.
Banging
The banging could also be the air ducts expanding and contracting when the blower turns on and off. They are typically made of metal so the change of temperature causes the loud popping as they change shape.
Grinding
Metal on metal is never a good sound. This could be a serious issue indicating parts that have come loose and are out of place. It could also just be poorly lubricated bearings in your furnace blower.
It needs frequent repair
Many of the above sounds could indicate a simple repair to get your furnace working again. When these โsimple repairsโ start becoming more frequent you have to consider the value of continuing frequent repairs versus the cost of a new furnace.
Thereโs no sense to continue shelling out money for repairs when your furnace is probably not operating at 100% efficiency anyway. Itโs better to think bigger and save more money in the long run by installing a new furnace.
Temperature varies between rooms
Do you need a space heater in some of the rooms in your house? When thereโs a noticeable difference in temperature between rooms itโs an indication your furnace is failing. As they get on in age it becomes more difficult to continue pumping air to the furthest places in your house. As a result, you might feel that some rooms donโt get the same heat as others.
Rising energy bills
A tell-tale sign of a furnace thatโs getting ready for retirement is a rising energy bill. Since heating and cooling account for almost 75% of your total bill, any inefficiencies in the performance of your units can be seen in an upward trend in the costs it takes to heat our home. When your furnace is older it tends to run more often and takes more energy to do the same job it did 15 years ago.
Itโs older than 15 years
One of the most obvious signs itโs time to replace your furnace is when it reaches the 15-year mark. Itโs not to say it canโt last another 5 to 10 years longer-it might! The truth is after 15 years, most furnaces begin to show signs of age.
Itโs common for energy efficiency to decline. Itโs generally more difficult for an older machine to operate the same way it did when it was brand new.
When you know your furnace has reached its 15th year itโs good to start considering replacement. Even if itโs in great shape, you can start planning on what your next move would be. If youโre considering making the switch to an electric furnace (or vice versa) it will take more planning since placement becomes an important factor.
Even if you just want to research a new model, having the time to check things out before it becomes an emergency is just good planning. You can get the best model for the best price and take your time in doing so. Don’t wait until you’re relying on your fireplace to heat the house!
If you have any questions about how to tell it is time to replace your furnace, feel free to call us for an over-the-phone consultation. Whether you need a furnace replacement or simple repair or just some solid advice, we got you covered.