Home Thermostats: What You Need to Know
  • Posted on September 20, 2022
  • By Rod Miller

It may be small, but it is mighty. This phrase perfectly describes a thermostat. After all, what other part of your home can have such a big impact on your comfort? A poorly programmed or incompatible thermostat can present many issues, so understanding how they work and how you can use this little appliance is crucial.

That’s exactly why we wrote this article. We’ll be giving you the complete rundown on all things thermostats. If you’ve got a question about them, you’ll find the answer here. We’ll cover the different types of thermostats, how they work with your HVAC system, how to choose the right one for your home, and whether you should try installing a thermostat yourself.

By the end of this article, you’ll almost have a basic knowledge of all things thermostat. So let’s get started!

What are the different types of thermostats?

The first thing you need to know about thermostats is that there are several different types available on the market. The three most common types of thermostats are mechanical, programmable, and smart. Let’s take a closer look at each one.

Mechanical Thermostats

Essentially, mechanical here means they are not programmable. You must physically set and change the temperature. These are the oldest type of thermostats and are not as common as they once were. A few subtypes fall into this category.

As a standard for about 200 years, mercury thermostats can be found in older homes. They use mercury because it is a metal that expands and contracts with changes in temperature. However, these types of thermostats are not recommended due to potential safety concerns and frequent inaccurate temperature readings.

You can purchase more modern mechanical thermostats that don’t use mercury. Instead, they use a bimetallic strip that expands and contracts to complete or break an electrical circuit. These are more accurate but still require manual adjustments.

Programmable Thermostats

Programmable thermostats are often considered a step up from mechanical ones as you can set them to automatically adjust the temperature for you. This is done by inputting data like the time of day and desired temperature. That way, whether you’re home or away, your thermostat will be working to maintain a comfortable environment. They are typically digital—meaning they have a display screen.

Many programmable thermostats will also allow you to set different temperatures for different times of the day and days of the week. For example, you may want the temperature lower when everyone is asleep or out of the house and higher when everyone is home and awake.

One thing to note about programmable thermostats is that they are not as effective if you don’t actually program them. If you never input any data or input incorrect data, it will operate as efficiently or to the schedule you would like it to, and you won’t experience the increased benefits.

Pro Tip: If you don’t want your thermostat to adjust and to stay at one temperature, i.e., stop its programming, Check for a hold feature. Using this setting will pause whatever heating or cooling schedule you have in place.

Smart Thermostats

The newest type of thermostat on the market is the smart thermostat. As you can probably guess from the name, these thermostats are WiFi enabled and can be controlled with your smartphone or other devices even when you’re away from home.

In addition to the features offered by programmable thermostats, smart thermostats often come with additional sensors that can detect whether or not someone is home. This allows them to make automated decisions about whether or not to heat or cool the house based on whether anyone is there.

Some smart thermostats also have learning capabilities. This means they will adjust the temperature for you based on your past behavior. For example, if you typically turn the temperature down at night, the thermostat will start to do this for you automatically.

Smart thermostats are the most expensive type on the market, but they also offer the most features and convenience. To learn more about these smart appliances, check out our guide here.

How does a home thermostat work?

Thermostats come in different shapes and sizes, but they all serve the same purpose: to regulate the temperature in your home.

A thermostat does this by sensing the temperature in your home and then sending a signal to your HVAC system to turn on or off as needed to maintain the desired temperature.

We like to think of it as an old-fashioned telephone switchboard. Remember learning about those in school? Picture the little old lady with glassed buried in electric cords and reaching to connect the wire that’s just out of reach.

In this metaphor, you are the caller, your thermostat is the switchboard operator, and your HVAC system is the call receiver.

You set the temp you would like, your thermostat senses the air, and then connects your call to the HVAC system that starts to heat or cool.

At a basic level, you must give the operator the correct information so they can connect the call, so it goes through without a hitch. Any breakdown in this process may result in a hot living room or chilly bedroom.

Now that we have that basis let’s move on to choosing the right thermostat for your home.

How do I choose a thermostat for my home?

The type of thermostat you need will depend on a few different factors. The most important is to understand what type of thermostat is compatible with your HVAC system.

A thermostat that works for a heat pump may not work for a gas furnace.

Once you know what type of HVAC system you have, you can start to narrow down your thermostat choices. Keep in mind that for a smart thermostat, your system will need a common wire.

The C wire, or “common wire,” is the electricity supply line that connects the thermostat to the system. It flows at 24 VAC power. A smart thermostat needs this power level to function.

If you’re unsure if your system is equipped with this wire or if it is compatible with the thermostat you just ordered online, reach out. Our friendly technicians can tell you if your thermostat will work with your HVAC unit.

Finally, review the choices we outlined in the previous sections and choose which is compatible with your schedule, lifestyle, and energy use. Not every thermostat makes sense for every home.

Can I DIY my thermostat installation?

DIY HVAC can be mixed bag. Thermostat installation can be done but can also be easily done wrong. Most of our thermostat maintenance calls come from home installation problems gone wrong.

If you plan on installing a new thermostat yourself, here are a few quick tips to ease your way.

  • Turn off the power. This should be step one for any HVAC project. Electrocution isn’t common, but it is very painful and potentially deadly.
  • Take a picture of any wiring you interact with before you start. This will help you remember which wire goes where if you get confused. Don’t force anything. All the pieces should fit snug but not require extra muscle to put in place.
  • Do extensive research. As we mentioned before, this includes the model of your thermostat, your HVAC unit, and how to properly install the new thermostat.

As always, if you have any issues or questions, our technicians are ready to help. We will install customer-supplied thermostats or the model we recommend at your request.

More Thermostat Questions?

So, there you have it. Everything you ever wanted to know about thermostats. If you need more information about picking out the perfect thermostat for your home, or if you’re having trouble installing or programming your current one, don’t hesitate to reach out.

At Rod Miller, we’re always happy to help our readers stay comfortable and save money on their energy bills at the same time.


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