Single Stage Furnaces vs. Two-Stage Furnaces

There are two types of furnace systems that you can choose: single-stage furnaces, and two-stage furnaces. Both have their own benefits and drawbacks, so it can be difficult to decide which one is right for your home.

In this guide, we will discuss the differences between single-stage and two-stage furnaces, so that you can make an informed decision about which type is best for you.

Single-Stage Furnace

A single furnace is a type of furnace that heats your home by using only one heat setting. It is a type of furnace that will either be in heating or cooling mode, and it cannot alternate between the two.

A single-stage will either be on or off, and it will not adjust its heat output depending on the temperature in your home.

It is important to note that a single-stage can be more efficient than a two-stage furnace because it does not have to work as hard to maintain the desired temperature.

The Pros and Cons of Single-Stage Furnaces

The following is a list of the pros and cons of single-stage furnaces:

The Pros:

Less expensive - Single-stage furnaces are typically less expensive. This is because the components are simpler, and there is less of a chance for something to go wrong.
Easy to operate - A single-stage is very easy to operate, and doesn't require any special knowledge or training. It also doesn't require you to switch between two different settings, making it easier to operate.
Smaller - It is typically smaller in size and can fit in smaller spaces, which can be a plus when having a limited amount of space in your home.
Lower repair - Single-stage furnaces are less complex, meaning they’re easier to repair and maintain. This also means that the parts for a single furnace are cheaper and more readily available.

The Cons:

Less efficient - These furnaces are less efficient because they only have one stage to work through. This means that they may not be able to heat your home as quickly or effectively.
Not suitable for larger homes - It may not be suitable for larger homes because it may not be able to generate enough heat to warm the entire home.
Waste of energy - Single-stage is more likely to cycle on and off constantly in order to maintain the desired temperature. It can lead to increased energy usage, and higher utility bills.

Two-Stage Furnace

A two furnace is a furnace with two different heat settings: high and low or hot and cold spots. The low setting is used most often, and the full power or high setting is only used when there is a need for more heat.

A two-stage furnace can be more efficient because it doesn’t have to work as hard to heat your home, which can save money on your energy bill.

The Pros and Cons of Two-Stage

Now that you know a little bit more about two-stage furnaces, let’s check out the pros and cons of installing one in your home.

The Pros:

More efficient - A two-stage furnace is more efficient because it uses both high and low settings to heat your home. This means that it doesn’t have to work as hard to generate heat, which can lead to lower energy, bills and a more comfortable home.
Suitable for all climates - It can be used in all climates because it has both a high and low setting. This makes it a good option if you live in a climate where the temperature varies throughout the year.
Larger size - They are typically larger in size, and can heat a larger area than a single-stage.
Improved air quality - They can also improve your home’s air quality because they come with a filter that removes particles from the air. It helps keep a steady flow of warm air, and circulates it better.
Lower energy use - Two-stage furnaces use less energy than single-stage, making them a more environmentally-friendly option.
Less noise - One of the best features of a two-stage furnace is that it runs quieter, and produces less noise. This is because the two-stage furnace operates at a lower speed most often, only kicking into high gear when it’s needed.
More even heating - A two-stage furnace also delivers more even heating throughout your home. This is due to the fact that the furnace doesn’t have to work as hard to heat your home, which means that the temperature is more consistent.

The Cons:

More expensive - They are definitely more expensive than a single-stage. However, it typically pays for itself in energy savings over time.
Requires professional installation - A two-stage furnace must be installed by a professional, so it may be more expensive to install than a single-stage.
Greater repair costs - This is because two-stage furnaces are typically larger in size, and have more parts. This also means that they are more complicated to repair, and may require the services of a furnace technician.

Things to Consider Before Buying the Best Furnace For Your Home

Now that you know a little bit more about their different types, it’s time to decide which type is best for your home.

1. Do you have a newer home?

If you have a newer home, a two-stage furnace may be a good option because newer homes are typically better insulated, and don’t need as much heat to stay warm.

2. Do you live in a climate with wide temperature swings?

If you live in a climate with wide temperature swings, a two-stage furnace may be the best option for you. It can be used in all climates, and has both low and high settings.

3. Do you have a large home?

If your home or property is particularly sizable, a two-stage furnace may be the best option for you. This is because it can provide more heat than a single stage.

4. Are you on a budget?

If you are on a budget, you may want to opt for a single-stage, because it is less expensive to both purchase and maintain, compared to a two-stage furnace.

5. Are you comfortable installing a furnace yourself?

If you are comfortable installing a furnace yourself, a single-stage furnace may be the best option for you. It is less expensive to install than a two-stage furnace.

If you are still unsure of which furnace is best for your home, contact a professional to help you make the decision. They will be able to look at your home and climate, and recommend the best option for you.

Differences Between a Two-Stage Furnace and a Single-Stage Furnace

Both of these types have their pros and cons, which is why it’s important to understand the differences between them before you make a decision.

The biggest difference between these two furnaces is the way that they heat your home. A single-stage furnace heats your home in one step, while a two-stage furnace takes two steps to heat your home. This is why a two-stage furnace is sometimes called a “two-speed” furnace.

Do I Need a Two-Stage Thermostat for a Two-Stage Furnace?

No, you do not need a two-stage thermostat for two-stage furnaces. A two-stage furnace can run on a single-stage thermostat. However, if you have a two-stage furnace, it is recommended that you use a two-stage thermostat to get the most out of your furnace.

A two-stage thermostat can help you save energy by adjusting the temperature in your home depending on what the furnace needs. A single-stage thermostat will not be able to do this, which can lead to increased energy costs.

How Do You Control a Two-Stage Furnace?

A two-stage is controlled by a two-stage thermostat. This thermostat has two different settings: low and high.

When the furnace is on low, it will run at 50% capacity. When the furnace is on a high, it will run at 100% capacity.

Frequently Asked Questions

What does a two-stage gas valve mean?

The two-stage gas valve is a valve that has two levels of heating. It can be used in all climates, and has both high and low settings.

Is a modulating furnace the same as a two-stage furnace?

No, a two-stage furnace is not the same as a modulating furnace. A modulating furnace has multiple stages of heating, and can adjust the amount of heat it produces depending on what the home needs. A two-stage furnace, however, only has two different levels of heating.

Can I put a variable-speed blower motor in my furnace?

No, a variable-speed blower motor is not compatible with a single-stage furnace. A two-stage furnace has a variable-speed blower motor, which is why it is more efficient.

What does a single-stage model furnace mean?

A single-stage model furnace is a furnace that has only one level of heating. It is less expensive than a two-stage furnace, but it can be less efficient because it has to produce more heat than a two furnace.

Do temperature fluctuations mean I need a two-stage furnace?

No, temperature fluctuations do not always mean you need two-stage furnaces. Depending on your climate and home insulation, you may only need a single-stage furnace.

After having read this guide, you now know the difference between a two-stage and a single-stage furnace. You also know which type of furnace may be the best option for your home. If you are still not sure, contact a professional to help you make the decision.