Buyers Guide & Information

Analog vs Digital Thermostats: Pros & Cons for Homeowners

Learn all about which option is best for cooling and heating your home.

by Ian Haynes

If you are looking for a way to save money around the house, or lower your carbon footprint, you may want to consider changing out your thermostat. With the technological advancements in home heating and cooling the analog vs. digital thermostats battle is shaping up to favor the digital methods.

There are several advantages of digital thermostats and few disadvantages. This article will examine the analog and digital thermostat types to help you decide if it is time to make a switch.

Line Voltage Systems

Line voltage systems are those that run boilers or furnaces. These systems only need the electrical jump-start to get going then use other means to maintain their performance. The thermostats are generally the same, though, and the systems tend to be in the 120-volt to 240-volt range.

Analog thermostats use mercury along with the internal thermometer to tell the system when to shut on or off. They can also use mechanical switches instead of mercury, which is a conscious environmental mechanism but isn’t entirely as accurate.

Digital thermostats for line voltage systems, like their low voltage counterparts, come in both programmable and manual types. Either way, you go there will be a digital interface for you to control (or program and forget) based on the temperature, time of day or season.

Low Voltage Systems

Low voltage systems are those that run on electricity, and the majority of homes and business will run these types of systems. Because they run on standard 24 volt (VAC) electrical systems, a heating and air conditioning system don’t use as much electricity as the line voltage systems, keeping your energy bill lower.

Analog thermostats plug into the system and mount on the wall allowing you to set the mode (heating, cooling or fan), and slide a dial to the desired temperature range. These thermostats have a thermometer built in to gauge the ambient temperature around the thermostat and turn the system on or off accordingly.

Digital thermostats also mount on the wall and plug into the system. You can use the touch-screen or other control methods to set the exact temperature, and the system will shut on or off according to the temperature reading of the thermostat.

Quick Guide – Our Top Picks


Best Digital Thermostat

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How Thermostats Work

The thermostat on your wall has one of the most crucial HVAC jobs around, yet it is a simple device. So how do analog and digital thermostats work? The devil is in the details.

Analog Thermostats

Analog thermostats use a bi-metal strip or a coil that is connected to the thermometer. When the temperature goes up, the metal expands, when the temperature drops, the metal constricts. This movement is what causes the contacts to connect.

Generally, the contacts are connected to a mercury bulb. The mercury acts as the conductive material to complete the circuit. On one side, the heater connections are waiting for the mercury. When the temperature drops the bi-metal causes the bulb to tilt towards the heating contacts where the mercury completes the circuit, and the heater comes on. The opposite tilt will result in the cooling system to come on.

Digital Thermostats

Smart Home ThermostatDigital thermostats don’t use mercury or glass bubbles. Instead, they use a little item called a thermistor. This device measures the temperature from the thermometer (or sensors) which is read and evaluated by the computer chip.

After a few algorithms, the temperature is displayed as a number on the screen. As the temperature increases or decreases, the cooling or heating portions of the system will come on (or shut off).

Everything is done using computer-based algorithms for a more accurate reading and control of the system, which will save you money on your energy bill in the long run.

Are You Scared of Going Digital?

Digital thermostats are a better option for most people. If you are upgrading your system, want more control over your heating and cooling or are just looking for accuracy and energy cost savings, digital wins every time.

The main deterrent, when speaking to people about digital thermostats, is installation and upfront costs. However, if you can turn a screwdriver, you can install a digital thermostat. If you can play Candy Crush on your smartphone, you can program a digital thermostat, too.

As for the cost, a digital thermostat is more expensive than a traditional analog unit, however, within the first year of running your HVAC system, the money you save on your energy bill will more than make up for the cost variance.

Home Thermostat Buying Guide

What should you look for when making your final purchase decision? We give you the important things to think about right here. Read below to find out more.

Control Voltage Type

portable thermostatAs we described above, the type of connections will matter the most. If you have an existing system and don’t know which model you have, it is easy to find out. However, for most of you, the thermostat and HVAC system will be low voltage.

For a quick check, see if your thermostat has an off position. If it does, it is low voltage. Line voltages don’t generally have an “Off” setting, just a “lowest setting” position. If you are still unsure, check your owner’s manual or with the manufacturer to be sure.

Central Heating System

For a heat-only system such as a furnace, boiler, or electrical unit, you will most likely need a line voltage thermostat. The best thing to do is to note which thermostat is already there and replace it with the same type. If you are looking to upgrade to a digital thermostat from an analog one, double-check that the new thermostat is designed for your system.

Thermostat Type Preference

For home and business use, the question comes down to your preference. Some people like the ease of use of the analog system or don’t have the desire for a smart-home integrated thermostat. On the other hand, if you are looking for a digital upgrade, that is your choice.

While no one can decide for you, it is best to go into the shopping experience knowing which style you are after. It will narrow down your choices and make finding the perfect thermostat much easier.

Accuracy & Energy Savings

When speaking of accuracy, you will want the heating or cooling to kick on at a specific temperature. All thermostats will have a variance of a few degrees.

This variance means that if you set the system to come on at 75 degrees, it may actually be 72 or 78 degrees when the system kicks on. Analog thermostats have a much higher variance than digital ones, making digital thermostats much more accurate.

Because of the accuracy, digital thermostats run systems more efficiently, which saves you money. Your energy costs will level out and, in most cases, will drop offering you substantial savings over the life of the thermostat.

Ease of Use and Installation

Thermostat on wallUnless your digital thermostat is a smart thermostat (such as a Nest), the installation for analog and digital thermostats are the same. You will put the wires in their correct slots and power on the unit.

If you can turn a screwdriver, you can install either a digital or analog thermostat with the same amount of effort. The difference will come in programming.

Analog thermostats aren’t programmable, so once you power the system and replace the faceplate, your job is done. However, for a programmable digital unit, You will have to set things like the date, time, system information, and other settings. It isn’t tricky, but it can be time-consuming.


Depending on the type of thermostat, manufacturer, and features, thermostats will come with a warranty. How long the warranty is will vary. If you are purchasing a more expensive thermostat you need to check on the warranty, return period, and how to make a claim before making your final purchase.

In the event you need the warranty, it is better to know at the start what materials, proof of purchases and costs for shipping you are responsible for.

Analog Thermostats Reviews

1. White-Rodgers Emerson 1F56N-444 Heating and Cooling Thermostat

White-Rodgers Emerson thermostats are installed in homes across the country. For over 50 years their thermostats have made their way into our homes and for a good reason — dependable, reliable service at an affordable price. The 1F56N-444 model is an update to the thermostats used in the past and has a similar size footprint to avoid painting or wall patches for install.

The bi-metal strip and mechanical gauges make the system more economical and efficient to keep your home at the correct temperature year-round. This analog thermostat is white to blend into the wall and has a simple interface to select mode, temperature, and fan controls.

A 3-year warranty protects your investment against defects in operations and craftsmanship. The low cost and simple installation will have you up and running in less than 10 minutes.

2. Suburban 232229 161154 Wall Thermostat

The low voltage heat-only thermostat from Suburban is one of the easiest installation thermostats around. Explicitly designed for heat-only systems, furnaces, and boilers, you can replace your existing thermostat within 10 minutes.

The thermostat features an off toggle (lowest setting plus one) and an easy to read temperature selector. Once installed, the thermostat will handle the rest. The low-cost and straightforward to install features are just part of the allure to the Suburban 232229. The other draws are the dependable bi-metal sensor, reliable furnace controls, and wall-blending color.

3. Dometic 3106995.032 RV Analog Thermostat

The Dometic analog thermostat brings HVAC controls to your RV and is one of the most trusted brands around. The Dometic 3106995.032 RV Thermostat is a specific replacement only model. To use this particular model number, your distribution box model number must be 3107541.009. This model is also design specific, meaning it won’t work with heat strips or heat pumps.

You can contact Dometic to find the specific replacement model for you if this one is not it (toll-free at 1-800-544-4881). Regardless of the actual part number, the HVAC controls of Dometic thermostats keep your RV at the ideal temperature during any season. With a temperature range of 32 to 90 degrees Fahrenheit (0 to 32 Celsius), you will have no problem finding the perfect temperature regardless of where you are.

Digital Thermostats We Like

1. Nest Learning T200577 2nd Gen Thermostat

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Best Digital Thermostat For Central AC

When it comes to smart thermostats, the title of “best” can be entirely subjective. With so many different features to compare, it can be hard to tell which one is best for you. However, with models like Honeywell and Ecobee competing for a spot in the market, Nest still stands tall.

It has all of the features you need, some you didn’t even know you needed (like ambient temperature adjustments, room sensors, etc.), and others that you just want. With Alexa voice controls, mobile app controls, and a sleek user interface that looks good on your wall, the Nest Learning Thermostat Gen 2 is a cut above.

The best part is that once the thermostat is installed in your home, it will begin learning your patterns and automatically adjusting your home’s temperature based on your habits. In the first year alone you can save over 30 percent on your energy bill.

2. Honeywell RTH2300B1012 Programmable Thermostat

If you have a heat-only system, you can upgrade to a digital thermostat, too. The Honeywell digital thermostat is ideal for homes with or without central air conditioning. You will find that the Honeywell is simple to install and takes virtually no time to program.

The actual controls are simple and straightforward, allowing you to get back to your day without worrying if you have a setting wrong on your heating system. The overall cost savings make the few extra dollars upfront even more worthwhile.

Need a Non-Programmable Thermostat for heat only? This similar Honeywell Pro Model is a great choice.

3. Coleman Airxcel 8330-3862 Digital Thermostat

The Coleman Airxcel Machine thermostat is designed to replace almost every RV thermostat from the last ten years. It uses a simple installation process (only two screws) and runs all 12-volt low voltage systems. The exception here is that it is not designed for heat pumps or zone controls.

If your RV needs to have the thermostat replaced, upgrading to the Coleman digital thermostat is a simple choice – do it. Even if your existing system uses the dual-red wire power system, this thermostat can accommodate. Cut down your heating and cooling costs starting today with this intuitive digital thermostat.

Need a more control in your RV Thermostat? This similar Coleman Model is a great choice

Thermostats: System Zoning

temperature thermostatYour home most likely has a single zone. This means you have one thermostat to control the temperature of the entire house. While this is convenient, it is also wasteful of energy resources. A zoned system uses multiple thermostats set up in zones.

The thermostats connect to a zone control panel which will activate dampers installed in the HVAC ductwork. By controlling each zone independently, you get the right temperature for the room or rooms you are occupying. The cost savings then, are found when you don’t heat or cool rooms that don’t need it, like the unused guest room, for example.

How to Install Thermostats

Honeywell thermostat wallIn over 90 percent of the cases, installing a digital and analog thermostat are going to be the same. Each manufacturer will have a slightly different installation procedure, so check the owner’s manual before you begin.

Each of the wires in your current system should be color-coded. However, the colors can fade, get caked with dust, and it may become difficult to tell the difference between blue and green, or orange and red.

It is advised that you mark each wire with a label for the port that it is removed from when taking apart your old thermostat.

From there, you will screw the mounting plate in place and pull the wires through. Following the labels, replace the wires in the correct ports and press the faceplate into position. When done correctly, the system should come on when you turn the power on and select a heating or cooling mode.

Switching from Analog to Digital

In virtually every case of replacing an analog thermostat with a digital one, there is very little you need to do differently. The only difference comes in the size of the thermostat. There may need to be some patchwork done to the wall to cover a larger hole or to paint the wall before the new installation.

Aside from these situations, installing a digital thermostat is identical to installing an analog one, which decides to upgrade to a more efficient digital thermostat even easier.


Replacing your thermostat shouldn’t be a chore, and it doesn’t have to be. While you can replace your thermostat with an exact exchange, it may be beneficial to upgrade to a digital thermostat.

The downside to the digital upgrade is the initial cost. However, with careful planning, you can offset the cost difference in just a few months. The amount of energy savings a digital thermostat provide compared to an analog thermostat are incredible.

Last Updated on July 16, 2021

Ian Haynes

Ian Haynes is an HVAC writer, and researcher. He has worked on hundreds of articles relating to home cooling, heating and air quality with a vast knowledge of the technical aspects of these types of appliances. Outside of his work, Ian likes exploring Brooklyn with his Labrador. Learn more about the AC Lab team here.