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  • Writer's pictureGBT Heating & Cooling

Problems Caused by an Oversized Furnace

If your heating system isn’t getting it done, there are a host of possible reasons why.

Once a furnace ceases to provide whole-house comfort, the most likely causes are these:

  1. Duct leaks

  2. Excessive wear and tear

  3. Age of system

  4. Clogged filter

  5. Problem with the ignition system or pilot light

  6. Poor quality system and/or installation

  7. Malfunctioning thermostat

  8. Lack of maintenance

  9. Incorrect sizing

Let’s focus today on the sizing issue, and assume your furnace is too large for the space it’s charged with heating. For years and years, it performed so well, you barely gave it a passing thought. But now, it’s struggling to keep you warm.

According to Home Energy Magazine, a third or more of all US heating systems are over-sized (under-sizing presents problems of its own).

Here are a few of the problems associated with over-sizing:

  1. Lack of whole-house comfort. When your furnace is too big, it will blast your home with too much conditioned air at one time. This can make your rooms feel too warm when your furnace is operating and lead to major temperature swings. On the flip side, the rooms farthest away from the furnace won’t be warm enough, thus causing the system to work harder to compensate.

  1. More frequent repairs. An over-sized system will cycle on and off more often than one that’s correctly sized. That leads to earlier-than-normal repair issues than you might see with a system that’s properly sized.

  1. Reduced lifespan. Excessive cycling can reduce life expectancy by half.

  1. Higher utility costs. Just as fuel efficiency decreases – and gas prices go up – when you drive shorter distances and turn your car on and off more frequently, the same thing happens with frequent on and off furnace activity.

  1. Noisy operation. When a unit is oversized and your ductwork is not modified accordingly, your system will operate at a higher decibel rating.

The best way to overcome these problems is to have your furnace correctly sized from the get-go. So, if you’re in the market for a replacement heating system, contact GBT Heating & Cooling today for a free in-home comfort analysis and new system proposal. We are your local and dependable home comfort specialists.


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