Can You Have Two Thermostats And One AC Unit?

Nick Durante
by Nick Durante

Nothing can make a home feel comfortable quite like a reliable HVAC system. Sometimes, that means that you need to upgrade to a new thermostat or add one. Can you have two thermostats and one AC unit?

You can have two thermostats and one AC unit if you wire them both to the air conditioner. This will let you adjust the temperature in your home from multiple areas in the house. However, you can only control separate areas of the house with two thermostats if you have a zoned air conditioner system.

In many cases, zoned AC systems are essential if you have a two-story home or a large ranch. It’s worthwhile to have two thermostats even if you don’t have a zoned AC system because of the convenience. Follow along as we explore everything that you need to know about pairing two thermostats with one AC unit.

Can You Install Multiple Thermostats?

You can install two thermostats if you have one AC unit. Different areas of the home have different temperatures throughout the day based on their location and how well-insulated they are. For example, basements are often colder than upstairs rooms and a single thermostat cannot adequately control both spaces.

A single AC with two thermostats can let you control the thermostat for separate areas of the home. This is often essential for large homes or homes with basements. Zoned AC units are compatible with two thermostats.

Standard air conditioners are sometimes compatible with two thermostats as well. However, it won’t let you adjust the separate temperatures for different zones throughout your home. You need to upgrade to a zoned AC system if you want to use two thermostats to program unique temperatures for different parts of your house.

How Does An AC With Two Thermostats Work?

Each thermostat controls a separate zone for an AC that has two. This includes both heating and cooling, and each thermostat only controls a specific area. The dampers within the system control the flow of air to each zone based on how you program whichever thermostat.

For example, you could set one thermostat to be cooler for a specific zone and set the other zone to be warmer. Zones typically include several rooms, such as a bathroom and bedroom that are nearby. It is common to find separate thermostats on nearly opposite sides of the house controlling two zones.

Your HVAC system won’t have to work quite as hard to heat or cool larger areas if you split it into two zones. This can help save money when it’s cold during the winter and hot during the summer.

Should a 2-Story House Have 2 Thermostats?

A two-story house should have two thermostats. Otherwise, you wouldn’t be able to adjust the temperature for each level of the house. This can lead to uncomfortable winters and summers as some parts of the house will be hotter or colder than others.

For example, your home’s second story will get hotter than the ground level or basement. Zoned HVAC systems are necessary for homes with two stories. Ideally, you should have a thermostat that controls the second story and one that controls the ground level and or basement.

It’s typically recommended that you program each thermostat to two degrees apart. For example, you may set your second-story thermostat to 66 degrees and the ground level or basement to 68 degrees. It takes some experimentation and patience to find the perfect sweet spot for each thermostat in your two-story house.

Two Thermostats One Zone

You can also install two thermostats for one zone in a house without a large zoned HVAC system. This is a great option, but only for convenience purposes. You won’t be able to control the temperature for separate areas of the house, but you won’t have to walk across the house to change the temperature.

Homeowners can also install multiple thermostats to control one zone in a house with a zoned system. However, this is somewhat uncommon and isn’t necessary in most cases. This would primarily be helpful if you lived in a massive home where the zones would be further apart, but it mostly just complicates things.

How Much Does It Cost To Have a Second Thermostat Installed?

It costs an average of $184 to install a second thermostat. However, it can cost over $350 depending on the model, location, and how much electrical work is required. The cost also varies based on who you hire if you don’t install the thermostat without professional help.

With that said, it’s worth the cost to hire an HVAC professional, especially if you have a zoned HVAC system. This requires electrical knowledge as each thermostat has to be connected to a separate zone. You will likely have to pay over $220 to install a second thermostat if you choose a smart device, such as a Nest.

Do Zoned Air Conditioners Cost More?

Zoned air conditioners typically cost more than standard HVAC systems. That is because they are more extensive and require more electrical work than a typical unit. Each thermostat has to be wired to each zone so you can control them individually.

Because of that, it can take much longer to install air conditioners, which can add to the labor cost. It can cost up to $15,000 to install a zoned air conditioner, but it depends on how big your home is. The size of your home ultimately determines how extensive your zoned AC system will be.

For example, you will need more dampers to distribute the air in each of the zones. This increases the cost of materials and labor as the installation will take longer. However, a two-zone or two-thermostat-zoned air conditioner may cost as little as $2,800 to install.

Why Won’t One AC Zone Work?

It could be a sign that there is a problem with your dampers if one AC zone won’t work. The damper motor may be faulty, worn, or broken. You typically need to replace the motor if it isn’t working, and it costs between $200 and $350.

If one zone doesn’t work, it could also be a sign that the ducts that lead to that zone are dirty. Air ducts can become clogged over time if you don’t clean them enough. It’s possible for the ducts leading to one zone to get dirtier quicker than the ducts leading to the other.

Replace the AC filter if one or both zones aren’t getting good airflow. Otherwise, it could be a sign that something is wrong with the thermostat that controls the zone in question. Change the batteries, reset the thermostat, or inspect the wiring if it won’t control the zone.

Summing It Up

You can have two thermostats and one AC. This makes it easier to adjust the temperature from different points in your home. You can also control the temperature for separate areas of the house if you have two thermostats and a zoned AC system.

Zoned AC systems are designed so you increase or decrease the temperature in different zones. The system features dampers that send the warm or cool air to that specific zone. It can cost up to $350 or more to install a second thermostat, but it typically costs roughly $184.

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Nick Durante
Nick Durante

Nick Durante is a professional writer with a primary focus on home improvement. When he is not writing about home improvement or taking on projects around the house, he likes to read and create art. He is always looking towards the newest trends in home improvement.

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