24 hr emergency service 519-652-0416
< Back

Is a Larger Furnace the Answer?

May 27, 2022

If it’s time to replace your current furnace, you may think the solution is to install a larger unit. However, there are several reasons this may not be the best option.

An oversized furnace can cause problems such as those listed below.

Just what is “short cycling”?

An oversized furnace may overheat and shut down before your house reaches the desired temperature.

This is referred to as “short cycling” and occurs because the furnace generates more heat than your home can use, causing the heat to build up in the furnace. Safety sensors cause the furnace to shut down in order to protect its components. There is far less risk of short cycling when your furnace is the correct size for your home.

How can a larger furnace be less efficient?

Your furnace will only operate at peak efficiency if it has sufficient time to cycle through a warmup phase. This does not occur if the unit is too large for your home. An oversized furnace quickly causes the temperature to rise. The thermostats register the desired temperature and signal the furnace to shut down. However, the temperature soon drops again, and the cycle repeats itself. Therefore, an oversized furnace is actually less efficient than one that is right for your home.

Won’t a larger unit have a longer lifespan?

This short cycling causes extra wear on your oversized furnace. It will need servicing more frequently and will likely not last as long as a unit that is the optimum size for your home. If your furnace overheats, something that often happens with an oversized unit, important components are likely to get damaged, resulting in costly repairs and a loss of heat when you most need it. You can save yourself money and aggravation with the correct furnace.

What about even heat distribution?

Do you notice that some areas of your home heat more quickly than others? This can happen even if you have the correct sized furnace. However, it will be even more noticeable if your furnace is too large for your needs. Slightly uncomfortable rooms can become far too warm. Other rooms may remain cold if the thermostat is located in an area that heats up first. The optimum sized furnace minimizes the problem of uneven heat distribution.

These are among the reasons why it’s important to consult an HVAC professional to help you find the right sized furnace for your home. With the correct furnace, you and your family will be more comfortable. Plus, your heating bills will be lower, a definite plus. 

For more information about choosing the correct furnace for your home, contact My Fireplace at either of our locations:

4026 Meadowbrook Dr., London, ON 


43993 Talbot Line, St. Thomas, ON