Signs of an Oversized Furnace
admin • December 7, 2011

Most people, when they choose a new furnace for their Wilsonville home, think that “bigger is better”. However, an oversized furnace can present just as many if not more problems than an undersized furnace. So, if you feel you may have overdone it in the past or you want to avoid making a mistake in the future, here are some signs that your furnace may be oversized.

Short Cycling

The most common sign of oversizing is short cycling. Short cycling occurs when your furnace turns on and off frequently because it reaches the thermostat setting so fast. Basically, your furnace is so powerful that it can produce what you need rapidly and then shuts off. But, because it does this, the temperature in your home is likely to cool much faster as well since the furnace isn’t on all the time.

Additionally, the on and off short cycling has a negative effect on your furnace, causing excess wear and tear on the system and eventually leading to extra repairs and in some cases early replacement.

High and Low Temperatures

When your furnace is turned on for a comfortable indoor temperature like 70 degrees F, the high and low temperature between cycles should be relatively close to that temperature. In an ideal situation, you shouldn’t even notice a fluctuation.

So, if the high temperature gets close to 75 degrees F and the low temperature is around 66 degrees F, you have a furnace much too large for the size of your home.

Furnace Room Issues

You might find that the space and exhaust given for the furnace are not sufficient either, especially if your previous furnace was replaced with this oversized unit. Backflow of a gas or oil smell or excess heat in and near your furnace room are both common signs that the furnace is much too large.

So, what should you do about your oversized furnace? If you have had that furnace for some time or just moved into a new home, it’s a good idea to have a new one installed. Have a proper load calculation done and then get a new furnace installed so you don’t have to worry about the system cycling on and off so often. If it’s a newer unit, call your heating technician and discuss possible options to reduce the negative effects of the miscalculation of its size.

A thermostat with a smiley face on it is covered in a knitted hat.
By Rodger Brown May 5, 2025
Learn four common signs that you need a new gas furnace.
The inside of an electric furnace is shown with the door open.
By Rodger Brown April 21, 2025
Learn the early warning signs can help you avoid a complete breakdown and keep your home warm, safe, and energy-efficient throughout the colder months.
A woman and a boy are playing with a dog on a couch.
By Rodger Brown April 7, 2025
Learn the top benefits of getting ahead of AC repairs before minor problems turn into major headaches. The post What Are the Benefits of Taking Action Early on AC Repairs? first appeared on Clean Air Act Inc..
A person is holding a remote control in front of an air conditioner.
By Rodger Brown March 24, 2025
Learn about the key steps involved in a ductless heat pump installation and why professional expertise makes all the difference. The post Steps for Installing a Ductless Mini Split System first appeared on Clean Air Act Inc..
A close up of a humidifier in a room with a plant in the background.
By Rodger Brown March 10, 2025
Learn about the benefits of a humidifier and how one of these unique systems can benefit your family.  The post What Are the Benefits of a Whole-House Humidifier? first appeared on Clean Air Act Inc..
The Clean Air Act Technician is holding a thermometer in front of a furnace.
By Rodger Brown February 24, 2025
Learn about three repairs that we get calls for when it comes to gas furnaces and the signs of each one. The post 3 Common Gas Furnace Repair Needs first appeared on Clean Air Act Inc..
Show More