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  • Writer's pictureTeam BlueBid

How to Know When to Replace Your Furnace

Most furnaces have a lifespan of 15- 30 years, especially with proper maintenance and care. However, there are signs that indicate it might be time to replace your furnace, instead of just repairing the issue. One common rule that experts recommend when it comes to repairing or replacing something is the 50% Rule — if the repair is over 50% of the cost for a full replacement, choose replacement. If your furnace has several of the following signs, consider buying a new furnace soon.

  • Your furnace is more than 15 years old. Furnaces increase their risk of issues as they age, especially after 15 years. Also, according to ENERGY STAR, when you replace a furnace that’s over 15 years old with an ENERGY STAR rated furnace, you can save an average 15% on your energy bill.

  • Your heating bill has increased. There are many problems that can cause an increase in your energy bills. But if you have been scheduling regular professional maintenance of your furnace every year and your air ducts are properly sealed, your energy bill shouldn’t increase dramatically. A steady increase in your heating bill over the years may indicate that your furnace is on its last legs. As internal parts wear out, your gas and electric bill may go up. If you notice a sharp rise in your bill, contact your local HVAC specialist.

  • Your furnace has been repaired frequently the past two years. Furnaces incur the most repairs during the last two years of their lives. If you’ve had more than two furnace repairs in the last year, it’s probably time for replacement. Also, if the repair cost is over 50% the cost of a new furnace, it is time for a new one.

  • Your furnace makes strange noises. If you furnace makes any rattling, popping, or banging noises when on, this can be a sign it is in need of replacement. Older furnaces make these noises at the end of their life. Also, if your blower turns on and off frequently or blows cold air, this is another indication your furnace should be replaced.

  • Your thermostat setting doesn’t keep you comfortable. Another sign is f some of your rooms are too hot or too cold or you constantly have to adjust the thermostat to stay comfortable. This might be because your furnace can no longer distribute heat properly throughout your house. A certified HVAC technician can confirm if the issue is with your thermostat or furnace.

  • Your burner flame is yellow instead of blue. If your furnace’s flame is yellow instead of blue, this could be a sign that your furnace is producing carbon monoxide. At the very least, the fuel is not burning as cleanly and efficiently as it should. Any furnace flame color that’s not blue can indicate incomplete combustion and a potentially dangerous situation, such as leaking gas and/or carbon monoxide. Carbon monoxide is an odorless, tasteless, and colorless toxic gas that is produced whenever fuel is burned. Exposure can be deadly. Signs that your furnace is producing carbon monoxide include:

    • streaks of soot around furnace

    • absence of upward draft in chimney

    • extra moisture found on windows, walls, or other cold surfaces

    • rusting on flue pipes or other pipe connections

If your furnace shows signs of producing carbon monoxide, leave your house and call your utility company to turn your gas off. Purchase a new furnace if the problem is serious.

Add up the furnace replacement signs

If your furnace has several of these signs, you should consider replacing your furnace soon.


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