Should I Choose a Gas or an Oil Furnace?

Posted: 2022-03-03

Replacing your furnace is a decision that you should make as soon as your system shows signs of inefficiency and a decline in performance. If your unit has been in service for over 12 years, it’s wise to start looking for a new furnace. Doing so not only rids you of the inconvenience and discomfort associated with running an old furnace, but also helps you save money in the long run.

Four Seasons Air Specialists is your reliable heating company in Woodbury MN. For over forty years, we have been helping homeowners establish energy-efficient homes, which includes installing the right furnace. Here is an age-old question you might want to take a look into as you decide to upgrade your furnace: What’s the better unit for my home: a gas or an oil furnace?


When deciding over a new furnace, it helps to know as much as possible about the fuel that will generate the heat. With that in mind, the two most common fuel sources are gas and oil. This article aims to give you relevant information on the main differences between these two types of furnaces.


Most homeowners choose gas furnaces because their fuel source is readily available through a connection to a gas utility’s supply line. Because of this interconnectivity, you have an uninterrupted supply of gas as long as you’re on top of your bills.

On the other hand, oil is not as common as gas, as you need to order as much as you need. It is often stored in a tank in or near your home, which means you have to regularly monitor the amount of oil left in the tank to make sure you don’t run out of fuel.


Furnaces’ efficiency levels are measured by their AFUE (annual fuel utilization efficiency)  rating. The rule of thumb is, the higher the number, the greater the efficiency. For example, a furnace with an AFUE rating of 99 means 99 percent of the fuel is converted into heat while only 1 percent of it goes up the chimney or elsewhere. High-efficiency furnaces or those with AFUE ratings of at least 90 are found both in gas and oil units. But keep in mind that oil typically produces more heat than gas, but gas is considered more efficient.


One of the main considerations you have to include is the price of the unit. From the get-go, an oil furnace will likely cost less than a gas-fired unit. If you are looking to have a high-efficiency system in your home, expect to pay a higher price than a standard unit. With that said, the benefits of a gas furnace usually outweigh those of an oil system, that’s why more people choose gas over oil.

When it comes to fuel costs, oil can experience fluctuating prices, especially during winter. Meanwhile, natural gas prices, which depend on global supplies, tend to be a little bit more stable.  Fuel cost is another factor why more homeowners have gas furnaces.


One of the more important factors you need to look into is safety. Gas is a highly combustible substance, making oil a safer choice. You have more safety concerns with a gas furnace than with an oil unit. For example, gas leaks have the potential to start fires or even explosions, especially if the gas has the chance to ignite.

In contrast, oil is not as much as a safety hazard than gas, but if there is an oil leak within your system, you may need specialized attention to address the issue to avoid aggravating the problem.

However, since both fuel sources are constantly being burned, they can create potentially harmful substances, including carbon monoxide. To avoid this risk, it’s best to have carbon monoxide detectors at home and have your unit regularly serviced to detect leaks and seal them off accordingly.

Cant Decide? Ask the Pros

We hope this article gave you some helpful information to guide you into making the right choice. But if you find it hard to pick the unit that’s best for your home, call Four Seasons Air Specialists. With over four decades of experience as your preferred Vadnais Heights heating and air conditioning installation company, we sure know what exactly your home needs.