Signs You Should Upgrade to a Two-Stage Furnace

Key Points 

• Two-stage furnaces offer a low output setting and a high output setting
• Two-stage furnaces are more efficient for larger homes and colder areas
• Although two-stage furnaces have a higher initial cost, they typically offer significant cost savings in the long run

What Is a Two-Stage Furnace and How Does It Work? 

If you’re considering upgrading your furnace, you might be wondering: Is a two-stage furnace worth it? While two-stage furnaces are often more comfortable and efficient, it’s helpful to understand how a two-stage furnace works so you can decide if it’s worth it for your home.

Most traditional furnaces are single-stage models, meaning they start at full power. Two-stage furnaces, on the other hand, have two settings: low and high power. This allows them to adjust their energy use and temperature output to better suit your needs.

Two-stage furnaces work by matching their output to the temperature level. For example, in milder weather, they’ll operate on the low setting, often using 50% to 70% of their output. When the weather gets colder, they’ll switch to the higher setting and use 100% output. This multi-stage system is more energy efficient and makes it easier to maintain a comfortable temperature in your home. 

Signs You Should Upgrade To a Two-Stage Furnace

If you’re considering one-stage vs. two-stage furnaces for your home, keep an eye out for these common signs that a two-stage furnace upgrade might be right for you:

1. Your home has uneven heating

If you live in a larger or two-story home, you may be facing chilly rooms and uneven temperatures. Single-stage furnaces often struggle to heat larger homes consistently and may run overtime to complete the job. A two-stage furnace is more efficient for heating large homes and can keep your home at the right temperature more consistently.

2. Your furnace turns on and off frequently

When your furnace turns on and off frequently, also known as furnace short cycling, it’s often a sign that your furnace output isn’t right for your home. For example, a furnace that’s too large will turn on, release excessive heat, and then shut off quickly. This rapid short cycling is inefficient and leads to increased wear and tear. Switching to a two-stage furnace allows your system to heat your home more efficiently, resulting in longer run times and lower energy use (and reducing wear and tear on your furnace).

3. Your utility bills spike in winter

Once the temperature drops, your single-stage furnace will turn on and operate at full power, resulting in a spike in winter utility costs. A more efficient two-stage furnace can reduce excess energy use during milder fall and spring temperatures. 

4. You want better air quality

Two-stage furnaces can operate at lower power for longer, making them better suited for air circulation, air filtration, and keeping your air ducts clean. This helps remove pollen, allergens, and other contaminants from your indoor air. They’re also more compatible with humidifiers and dry out your air less than single-stage furnaces.

5. Your current furnace is 15+ years old

Most furnaces last 15 to 20 years with proper furnace maintenance. If your furnace is reaching the end of its expected lifespan, it’s a great time to consider upgrading to a more energy-efficient two-stage model.

6. You’re looking for a quieter furnace

Single-stage furnaces tend to be loud when they switch on. Since two-stage furnaces offer a low power setting, they’re quieter and can make a more comfortable home environment.

When a Two-Stage Furnace May Not Be Necessary

While an energy-efficient heating system offers many benefits, there are cases where it may not justify the cost. These are some common circumstances where a two-stage furnace may not be necessary.

Smaller or well-insulated home

Smaller and well-insulated houses tend to require less energy for heating, meaning they won’t necessarily feel the full benefit of a two-stage furnace. While a two-stage furnace can still be highly energy-efficient and quieter, it may take longer to realize the full cost benefits.

Mild climate

Most of Indiana is fairly cold in winter, with average lows around 23 degrees in the north and central areas. However, if you live in a milder area like Evansville and you don’t rely heavily on your furnace for extended periods, it may not be worth investing in a two-stage furnace.

If you’re planning to move soon

Two-stage furnaces are an investment, and it typically takes a few years for the cost savings to return. If you’re planning to move in the next few years, it may be more cost-effective to repair your existing furnace or opt for a single-stage furnace with a lower upfront cost.

How Much Does a Two-Stage Furnace Cost? 

Two-stage furnace costs vary significantly by make and model, with unit costs ranging from $2,500 to $4,000 or more. After installation, this typically means $500 to $1,000 more than a single-stage furnace.

However, two-stage furnaces are significantly more cost-effective in the long run. It’s estimated that two-stage furnaces save you 10% to 15% in energy use, which typically makes them more affordable over the 15- to 20-year lifespan of your furnace. Exact cost savings will depend on the model and your energy use, but they are usually higher if you have a larger home or live in a cold part of Indiana and use your furnace frequently.

Looking for even more ways to boost your energy savings? Consider a two-stage Energy Star furnace to improve efficiency and reduce energy bills.

Call Dugan for Furnace Upgrades and More in Indiana

Whether you need to replace a broken furnace or are browsing for energy-efficient upgrades, Dugan is your go-to for Indiana furnace solutions. We install, maintain, and repair all furnace makes and models, including two-stage furnaces. Contact us today to schedule your appointment and discover how a two-stage furnace can save you money while making your home more comfortable than ever.

Frequently Asked Questions

Can I replace a single-stage furnace with a two-stage one?

Yes, if you currently have a single-stage furnace, you can hire an HVAC pro to replace it with a two-stage furnace. Depending on your thermostat model, you may need to upgrade it to be compatible with the new system.

Does a two-stage furnace last longer?

Two-stage furnaces can last longer than single-stage furnaces because the lower setting improves efficiency and reduces wear and tear. While it depends on the furnace, your maintenance plan, and your usage habits, some two-stage furnaces can last 1 to 3 years longer than comparable single-stage models.

Do I need a special thermostat for a two-stage furnace?

Yes, you’ll need an HVAC thermostat that offers multi-stage heat to properly operate your two-stage furnace. While an older thermostat can still operate the furnace, it will only allow it to run on the high setting, which takes away the advantages of a two-stage furnace.

Dan Dugan

President
Dan Dugan is the President and co-owner of Dugan Air Heating & Cooling. A licensed HVAC professional with over 25 years of industry experience, Dan brings extensive technical expertise and leadership to the company he and Sue founded in 2009. He remains deeply involved in training, innovation, and maintaining the company’s reputation for integrity-driven service across Central Indiana.