4 types of furnaces you’ll find while house hunting

blue and white wooden house covered with snow

Popular types of furnaces to know when deciding on a new home

If you’re searching for a new home, you’ve probably already come face to face with plenty of different kinds of furnaces. 

While you may not choose a home just for its furnace, knowing how your home will heat itself is a big part of the puzzle. 

A home furnace determines a big chunk of what your home maintenance will look like, so it’s best to know a little about what you’re getting into now before you experience buyer’s remorse.

This article goes over the basic idea of what a furnace is and the most common types you’ll find. Then, we’ll run down the pros and cons of each one. 

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Key takeaways:

  • Every furnace is safer and more efficient with proper routine maintenance
  • Propane, oil, electric, and gas are the common furnaces found in homes
  • Each one comes with pros and cons
  • While gas is considered the most cost-effective way to heat a home, you need to be in an area with a hookup
  • Electric and propane seem like the economical options at first glance, but they have hidden costs

What is a furnace?

Ask a kid (and some adults), and the furnace is that big, creepy appliance in the deep recesses of your house that makes weird noises and is hooked up to all those ducts. But it does more than just keep your kids out of the basement. 

A furnace is a mechanism in your home that converts energy to heat so every room is comfortable for the humans and pets who live there. It keeps pipes from freezing and your home safe in the winter. 

While the first furnaces were powered by wood and coal, modern homes in the US use more contemporary methods to keep things toasty.

How do you know when to replace your furnace?

It’s hard to know whether a furnace needs service or replacement unless something goes wrong. 

That’s why it’s a good idea to make regular inspections by an HVAC technician a regular part of your home maintenance. 

Ideally, you would do this every year. 

Most furnaces will last around 20 years, according to the home maintenance master, Bob Vila. But proper maintenance will extend that time even more. However, some furnaces stop working closer to the 15-year mark depending on the type of furnace, ductwork, and maintenance issues. 

Common signs that your furnace is on the fritz include:

  • A sharp increase in your energy bill without any usage changes
  • Dirt, rust, and soot in your home’s air
  • Uneven heating throughout your home
  • Cracking or rusting on the furnace unit

If you’re paying for constant furnace repairs, it may be time to consider replacing your system. 

The good news is that modern high-efficiency furnaces may save you hundreds of dollars per year in energy costs. The US department of energy studied the effect on your wallet of high-efficient furnaces and found that, as long as the installation doesn’t cost more than $1,200 above the price to install other furnaces, you could save between $300-$500 a year. Add that up over the lifetime of your furnace and you’re looking at some serious cash. 

What does proper furnace maintenance look like?

The specifics of furnace maintenance are different based on the type of furnace you have. 

However, the steps for ensuring that everything is running safely, smoothly, and efficiently are pretty straightforward. 

Here’s the rundown:

  • Dust and wipe floor vents
  • Replace the air filter every three to six months 
  • Regularly clean flame sensors and burners
  • Inspect the heat exchanger for cracking or leakage
  • Lubricate the blower and inducer fans if they aren’t rotating freely
  • Clean the humidifier
  • Inspect all electrical wires and controls for any loose connections
  • Check that the thermostat is operating properly
  • Inspect and clean air registers
  • Inspect flue pipe for cracks of blockages
  • Inspect ductwork to make sure it looks clean

While homeowners can take care of tasks like changing filters and conducting visual inspections, it’s important to have a professional checkup done at least once a year. 

The good news is that most local HVAC companies offer low-cost annual maintenance packages that allow you to get a free inspection with some upgrades and repairs covered. 

Put signing up for one on your list of steps to take after closing.

There’s one more critical task that every homeowner can handle! Ensure your carbon monoxide (CO) detector works properly once a month. Replace the batteries right away when necessary.

crop unrecognizable housewife placing saucepan on burning stove
Gas is an efficient and cost-effective way to heat your home but is expensive to install if your home or neighborhood doesn’t already have a gas line available

How a propane furnace works

A propane furnace converts liquid propane into gas that pushes warmth across your system’s heat exchanger. The concept is very similar to the way that any type of forced-air furnace heats a home. 

One of the perks of a propane furnace is that it tends to be suitable for a tight space because it’s very compact. It also has a stronger heating capacity compared to natural gas. 

Propane furnaces are actually pretty rare. While they are considered efficient, they are typically only used in areas where gas or oil aren’t readily available due to the hassle of storing propane.

The prose of a propane furnace

  • Propane burns cleaner than oil and gas
  • Propane vapor is nontoxic if inhaled

While propane vapor is not poisonous, it is an asphyxiate gas and high concentrations will displace oxygen in your lungs. 

  • Relatively cheap fuel source

The cons of a propane furnace

  • Propane has a lower heat output than oil
  • You need to purchase or rent a tank

How an oil furnace works

Oil is extremely popular in some of the coldest climates because it offers fast, consistent heat. 

An oil furnace turns oil into a fine mist as it moves into the combustion chamber and ignites. Once the chamber heats up, air absorbs the heat before the furnace blows heat through the ducts to every room of the house. 

Only natural gas furnaces are more popular than oil furnaces.

The pros of an oil furnace

  • Oil heats larger spaces efficiently 
  • Oil furnaces are known for their longevity 
  • Oil does not produce carbon monoxide and other poisonous gasses. 
  • Oil furnaces also reduce explosion risks compared to gas 
  • You don’t need any pipeline infrastructure to be able to use it 

The cons of an oil furnace

  • You need to schedule oil deliveries to your home 
  • The price of oil (and so the cost to heat your home) fluctuates with supply and demand

How an electric furnace works

If you’ve ever used a hairdryer, you have some idea of how an electric furnace works. 

Electric furnaces pull air into your heating system using a heat exchanger. Once the air reaches the heat exchanger, it is warmed by electric heating elements before being pushed into your home’s ductwork by a blower.

The big draw of an electric furnace is that the upfront cost of having one installed in your home is much lower compared to other options. 

You might pay half the cost of a gas furnace by going electric. 

However, your monthly electricity bill with an electric furnace is likely much higher than what you’d pay for oil or natural gas. 

But, you can install a dual fuel furnace that combines the efficiency of an electric heat pump with the performance of a gas, oil, or propane furnace.

The pros of an electric furnace

  • Electric furnaces are known for being quiet and durable 
  • You’ll pay much less for a new electric furnace when compared to other types of furnaces 
  • Electric furnaces don’t emit carbon monoxide in the home
  • Electric furnaces also retain more of the heat that’s generated instead of venting it out

The cons of an electric furnace

  • However, electric furnaces can be slow to heat homes. Generally, heating a home using an electric furnace is much more expensive than other options over the long haul.

How a gas furnace works

While oil and gas are both popular options, a natural gas furnace is actually the most popular way to heat a home in the United States. 

But you’ll need a gas line first. 

A forced-air gas furnace works by using a burner to ignite the gas  then transfers heat through an exchanger that pushes the warm air through the ducts. 

As warm air fills each room, the dense air gets pulled into the furnace’s return ducts.

Gas furnaces are popular because of their relative lower cost and higher efficiency. 

There’s also no worry over running out of fuel the way homeowners do with oil furnaces because gas furnaces are constantly hooked up to the source. 

Some gas furnaces are modulating furnaces that constantly adjust temperature settings for ideal performance instead of shutting on and off like a single-stage furnace.

The pros of a gas furnace

  • Gas is considered the most cost-effective way to heat a home in most parts of the country 
  • Gas heats a home quickly and evenly 
  • A gas furnace is easy to pair with air conditioning

The cons of a gas furnace

  • It’s one of the pricier options to install 
  • Homes need plenty of extra space for ductwork to be able to accommodate gas heating systems 
  • You’ll need to be vigilant about carbon dioxide when a gas furnace is running 
  • Finally, gas furnaces have shorter life spans of around 15 years

Weighing the good and bad of different types of furnaces

Make sure the furnace room is one of the first stops you make when touring a home. 

If you’re shopping for a home, you can take comfort in the fact that the previous builder or owner probably chose the ideal furnace and heating system for the layout, location, and climate of any place that you fall in love with. 

Of course, upgrading to a new furnace with high efficiency is always a possibility if you inherit an outdated system. If you choose to upgrade your system after you buy your home, though, there are plenty of state and federal tax credits and rebates available.

We know buying a home is a big deal. That’s why we built a real estate experience designed to keep it as simple as possible. If you still have questions about the homebuying process, talk to a Flyhomes Agent today , and we’ll walk you through every step with a dedicated expert at each turn.  

About the author: As the son of a construction contractor and a former property manager, Scott knows how to keep the lights on and the water running. In addition to Flyhomes, he has written for Angi, HomeLight and HomeAdvisor. His hobbies include fixing things around the house, baking things up in the kitchen, and spending quality time with his wife and daughter just about everywhere.

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