This blog was updated July 2025.
Roughly 90 percent of American households have an HVAC system.
For your HVAC to run efficiently, all the various parts of the components must be working well. One such part is the thermostat, which is your line of communication to the system. It’s why you need to replace your thermostat the moment yours becomes faulty.
As winter approaches, you want to make sure that your HVAC’s thermostat is in good shape, or you risk coming home to a chilly home. The problem is that most people don’t know when it’s time to get a new thermostat until it’s too late.
That’s why we’ve created this post. By the time you’ve finished reading, we hope you’ll recognize some of the top telltale signs that it’s time to replace your thermostat.
Let’s delve into it.
1. Your HVAC Keeps Turning On or Off
As we hinted earlier, the primary function of a thermostat is to communicate with your HVAC. It sends signals to your HVAC to either increase or decrease the temperature. If your HVAC has stopped responding to the thermostat prompts, it’s highly likely that the thermostat has a problem.
Usually, the wiring inside your thermostat can become damaged or frayed. This compromises its connection to the HVAC. Hire a professional HVAC service professional who should be able to diagnose the problem and tell you whether the thermostat is due for a replacement.
2. Faulty Thermostat Readings
Correct thermostat readings ensure that your indoor spaces don’t get too hot or cold. When your thermostat starts to register incorrect temperatures, then it may be time to start thinking of getting a new one.
To verify whether the temperature is correct, test its reading with a portable indoor thermometer. If the readings are wrong, then the thermostat’s sensor might be malfunctioning. The issue could be old age, a manufacturing defect, or misuse.
3. Suspiciously High Energy Bills
Like most people, chances are you’re always looking for ways to lower your energy bill. An inefficient HVAC can have the opposite effect. You find that you have to pay a higher energy bill than usual.
Many times, the thermostat is the culprit. A thermostat that’s not correctly reading the temperature will usually cause your HVAC to overwork. The more times the unit cycles per hour, the higher the power it consumes.
During your regular professional HVAC tune-up, your technician will let you know whether you need a new thermostat to fix the problem.
4. Constant Temperature Shifts
A faulty thermostat typically has a hard time maintaining settings. It may continuously change temperature settings without warning.
Try lowering the thermostat settings for a test trial and see what happens. If the same problem occurs, call a technician to check the thermostat.
5. Thermostat Is Too Old
As with all other systems, your thermostat will eventually become old and outdated. The lifespan of most home thermostats is 10 years. However, you may need to replace yours sooner as newer, more efficient thermostats enter the market.
You may, for instance, want to replace a non-programmable thermostat with a programmable option. The latter type of thermostat works remarkably better than the outdated non-programmable thermostat. Programmable thermostats feature advanced technology that has a lot more programming options.
6. Thermostat Fails to Respond to Changed Settings
The moment you adjust temperature settings, your thermostat must promptly respond to those changes. Typically, you’ll hear small clicking sounds when you make the changes, and your HVAC system immediately starts.
If your HVAC system doesn’t come on the moment you make these changes, then it probably has a problem and needs replacing.
7. Your HVAC System Short Cycles
Short-cycling is one of the top reasons for replacing old thermostats. The problem happens when the system shuts off earlier than appropriate, failing to complete a full cooling or heating cycle.
If this keeps happening, then it’s probably time to replace the thermostat.
Shopping for a New Thermostat
One of the first things you’ll realize the moment you start searching for a new thermostat is how many options there are in the market. How do you identify the right option for you? Here are two helpful tips:
Choose a Suitable Thermostat Type
Homeowners have a variety of options when it comes to choosing a thermostat type. Each of these options has different features, so opt for the one that works best for you. Below are some of the top thermostat types in the market today.
a. Learning or Smart Thermostats
These thermostats are programmable but don’t need you to do the programming. As you use them, these thermostats learn your preferences and create a schedule that aligns with those preferences.
b. Remote Energy Management Thermostats
With a remote energy management thermostat, you can set, program, or monitor your HVAC system using your smartphone, tablet, or computer.
c. Programmable Thermostats
Programmable thermostats automatically adjust the set temperatures throughout the day. In so doing, they make the most efficient use of HVAC.
d. Digital Non-programmable Thermostats
These thermostats come with a digital readout (DRO). They’re ideal for people who like manually controlled settings but want the convenience of an LCD display.
e. Mechanical or Manual Thermostats
A mechanical thermostat allows you to control the temperature settings manually. They’re ideal for homeowners who prefer fixed temperatures and who are often at home.
Know the Features to Look For
As thermostats become increasingly advanced, newer models come with unique abilities. Some of the favorite features for most customers include:
- App Control
- Auto Changeover
- Automatic Temperature Changes
- Helpful Reminders
- Easy-to-Use Controls
These features determine the cost of new thermostats. The more features a thermostat has, the higher the price you may have to pay for it.
Know When to Replace Your Thermostat
As you prepare for the cold season, consider whether you need to replace your thermostat early enough. If you’ve noticed any of the signs we discussed in this article, chances are it’s time to start shopping for a new thermostat.
Are you interested in reliable and cost-effective HVAC services? Please contact us today
FAQs
How do I know if my thermostat is broken?
Common signs of a failing thermostat include:
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Incorrect temperature readings
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HVAC not turning on or off properly
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Unresponsive controls
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Frequent short cycling
If your HVAC isn’t acting as expected, the thermostat is a good place to check first.
How long does a thermostat last?
Most thermostats last around 10 years. Older models may wear out sooner or become obsolete due to advancing technology. Upgrading to a smart or programmable thermostat can improve efficiency and comfort.
Can a faulty thermostat cause high energy bills?
Yes. If your thermostat isn’t reading temperatures accurately or fails to maintain consistent settings, it can cause your HVAC system to overwork, leading to higher utility bills.
Is it worth upgrading to a smart thermostat?
Smart thermostats offer energy-saving features, remote access, learning algorithms, and more. If you travel often or want better control over your energy use, the upgrade is often worth the investment.
Can I replace a thermostat myself?
If you’re replacing a simple non-programmable model and you’re comfortable with electrical work, DIY replacement may be possible. However, for complex systems or smart thermostats, hiring a professional ensures proper installation and safety.