Thermostats are essential to any heating, ventilation, and air conditioning (HVAC) system, allowing you to keep your home comfortable in all kinds of weather. But a thermostat won't change temperature and can throw off your entire HVAC system. 

In this article, we'll discuss the various causes of a thermostat not changing temperature and provide troubleshooting and repair tips to help you get your HVAC system back up and running. Whether you're experiencing erratically fluctuating temperatures or just one that won't budge, this guide has covered you. Let's dive in! 

What Is A Thermostat, What Does it Do, and How Does it Work?

Thermostats are a type of control device that is used to maintain a constant temperature. Thermostats use a temperature-sensitive element called a bimetallic strip to regulate the temperature. The temperature-sensitive part acts as a thermostat.

The bimetallic strip is a thin metal strip coated with a substance that changes shape at a specific temperature. This strip connects to a thermostatic switch. As the temperature changes, the strip bends and moves the control from one position to the other.

The thermostatic switch has two different functions: ON and OFF.

• The thermostatic switch turns on when the strip bends and is in its ON position.

• The Thermostatic switch turns off when the straight strip is in its OFF position.

The thermostat has two main components.

• First, it has a heat-sensitive element that controls the room's temperature.

• Second, it has a thermostatic switch.

A thermostat operates by sensing the ambient air temperature around it. It turns off the heating system when the room is warm. However, it turns on the heating system when the room gets cold. When the temperature rises above the desired level, it causes the thermostatic switch to turn on the heating system. When the room gets too cold, it causes the thermostatic control to turn off the heating system.

The thermostatic switch has three states.

• First, the thermostatic switch is in its OFF state. It is in this state when the temperature is higher than the desired setting. It is also in this state when the thermostat is first activated.

• When the thermostat turns on, the thermostatic switch turns to the ON state. It is in this state when the room temperature reaches the desired setting.

• When the temperature drops below the desired setting, it causes the thermostatic switch to return to its OFF state.

Thermostatic switches can function as thermostats. Homes are heated and cooled with the help of thermostatic switches.

There are many types of thermostatic switches, such as the following:

1) Expansion-type switches

2) Compound-type switches

3) Direct-acting thermostats

4) Reciprocating thermostats

5) Single lever-type switches

6) Double lever type switches

7) Trip lever switches

8) Single-lever thermostats

9) Double lever thermostats

10) Vacuum the thermostat.

Two types of thermostats

1. Thermostatic Switch – Thermostatic switches have a heat-sensitive element that turns the heating on or off. Thermostatic switches are used to regulate the temperature of a room.

2. Thermostatic Valve – Thermostatic valves have a thermometer with a pointer. Thermostatic valves are used to regulate the flow of water.

7 Reasons Why Your Thermostat Is Not Working

A thermostat is a device that regulates the temperature in a room. It consists of a metal rod (sensing element) inserted in the room's wall or ceiling and a temperature control knob at the top. The rod is connected to the heating system and is influenced by changes in the room temperature. As the room gets hotter, the rod warms and turns the knob clockwise to reduce the temperature or counterclockwise to increase it. The thermostat is usually set to maintain a constant temperature within a particular range.

If the thermostat has stopped working, the rod will no longer react to changes in room temperature. If you have a thermostat that is no longer working, it may be due to one of the following causes:

1. The thermostat no longer functions properly due to its advanced age. - Reasons Why your Thermostat is Not Working

Age is one of the most common factors contributing to a malfunctioning thermostat. Because of the normal wear and tear that occurs over time, the thermostat's performance may deteriorate over time. Keep in mind that thermostats are not designed to last indefinitely. On top of that, toying with an old model can be a waste of time and energy, resulting in financial loss.

If the thermostat is not functioning correctly, it is probably time to replace your older model with a more up-to-date one. Suppose you are still using a mechanical thermostat, the most fundamental type. In that case, consider upgrading to a programmable thermostat that is simple to operate and straightforward to connect to the system you already have.

2. The thermostat does not function properly due to faulty wiring or defective parts. - Reasons Why your Thermostat is Not Working

A malfunction of your thermostat can be caused by a loose connection, becoming disconnected, or faulty wiring. Examine the wiring inside of your thermostat and secure any wires that appear to be hanging loose. If you are having issues with the wiring in your home, you should either replace the cables that are worn out or speak with a knowledgeable HVAC professional.

The mechanical thermostats contain an electrical resistor device that communicates with the thermostat to let it know when the system should be off. If it is not functioning correctly, it may prevent your furnace from turning on and off at the appropriate frequency. It can adjust the electrical resistor devices, and an amp is a tool for determining the ideal configurations. 

Meanwhile, Programmable thermostats typically have a built-in anticipator that can be programmed independently and are equipped with automatic setting capabilities.

3. There was an error in the programming, so the thermostat is currently unrepairable. - Reasons Why your Thermostat is Not Working

There may be an error in the thermostat's programming if the system is not functioning correctly. It frequently happens when an unexpected interruption in the flow of electrical power may disrupt the normal operations of the programming chips contained within the thermostats. You will need to reprogram the chip to function correctly again. There are also programmable thermostats with memory systems that are more robust and continue to work typically even if the power goes out.

4. The batteries in the thermostat are dead, so they will not function properly until they are replaced.- Reasons Why your Thermostat is Not Working

When the power goes out, the thermostat's batteries help keep the settings they were in. Even though these batteries are supposed to have a lifespan of at least one year, many homeowners only bother to replace them once it's too late. When the batteries in the thermostat are getting low, it will interfere with its ability to control the heating and cooling processes in the home.

When the batteries in most programmable thermostats begin to run low, a warning symbol displays on the thermostat. When the screen goes black, it indicates that the batteries have no more life left. The thermostat can no longer control the heating, ventilation, and air conditioning system, which has resulted in dangerously high temperatures. Depending on the type of thermostat, you will need either AA or AAA alkaline or lithium batteries to replace them.

5. Because of the location in the building, the thermostat needs to be fixed.- Reasons Why your Thermostat is Not Working

Your thermostat may be malfunctioning because it's installed in an inconvenient location. In general, you should avoid installing the thermostat in areas with direct sunlight or close to exterior doorways, as doing so will compromise its ability to perform its intended function. In addition, you need to ensure that the thermostat is mounted on a wall with a high thermal coefficient.

Move your thermostat to a more convenient location if you believe its current placement is not optimal. Positioning your thermostat in a central position so it can achieve the most even temperature distribution will provide the most significant level of comfort.

6. A problem with the circuit breaker is the cause of the thermostat's inability to function correctly.- Reasons Why your Thermostat is Not Working

A circuit breaker switch ensures your home's safety from dangerous electrical surges. Your thermostat won't function properly if it continues to malfunction due to a circuit breaker that keeps tripping. The relocation of appliances is necessary to lessen the load on the electrical circuit. Engage the services of an electrician to carry out a comprehensive upgrade, which might involve the addition of additional circuits to your system.

Because of normal wear and tear, specific circuit breakers trip for no other reason. If you begin to experience regular circuit outages, smell something burning, or notice signs of deterioration around the circuit breaker, you should immediately call a professional for assistance. If you ignore electrical problems in your home, you risk having a fire or other hazards occur. Hold off on investigating and fixing the issue until the circuit breaker has been turned off.

7. Dirt and debris have prevented the thermostat from functioning correctly.- Reasons Why your Thermostat is Not Working

Dust will inevitably gather inside your thermostat as time passes. A buildup of debris and dirt could cause an inaccurate temperature reading, leading to an unexpected system failure. To clean the thermostat, remove the cover and gently clean its interior components, including the bimetallic switch and the coil contact areas. It will bring the thermostat back to its original state.

DIY Troubleshooting Tips For Your Thermostat Not Working.

• Change Batteries- DIY Troubleshooting Tips for Thermostat Not Working
  
  
  
  
  

Changing the batteries in your thermostat is one of those seemingly small tasks that can significantly impact how effectively your home is cooled. Install new batteries in your thermostat if you find it malfunctioning. Changing the batteries is a quick and easy process that only takes a few minutes to complete. Removing the thermostat from the wall is necessary to check the batteries contained within it. After taking the thermostat away from the wall, you will need a screwdriver to remove the cover over the battery.

• Check the Circuit Breaker as the Second Step- DIY Troubleshooting Tips for Thermostat Not Working
  
  
  
  
  

You should check the circuit breaker if your thermostat is not functioning properly. The thermostat receives it correctly from the circuit breaker, the responsible party in this relationship. If the circuit breaker is tripped, the thermostat will not operate as it should. To check the circuit breaker, you will first need to find the breaker box in your house and determine which breaker controls your thermostat. After locating the circuit breaker, you must turn it off and back on again.

• Check the Programming on the Thermostat- DIY Troubleshooting Tips for Thermostat Not Working
  
  
  
  
  

An error in the thermostat's programming may cause it not to function correctly. The thermostat must have the correct settings programmed into it to work correctly. Programming a thermostat can be challenging, especially if you need help determining which mode best suits your house and its needs. You need to consult the owner's manual to ensure that the temperature setting on the thermostat is accurate. You will find information on navigating the controls on the thermostat within the owner's manual, allowing you to set it to meet your requirements. Here you will find more information about how to readjust the temperature on your thermostat.

One of the most typical errors in programming occurs when the thermostat for a heat pump system is used for the heating system instead of the furnace or vice versa. It is not common knowledge that thermostats can be made to work with various other pieces of apparatus. If the thermostat for your furnace is working the way it needs to work for a heat pump, then your furnace and air conditioner will work against each other to provide you with the desired temperature. As a result, your utility bills skyrocket.

Moreover, a Smart Thermostat can automatically adjust the temperature in a home, which considers the homeowner's patterns of presence and absence. The homeowner can turn this function off if they choose, although it is designed to improve energy efficiency.

And as a final step, ensure the thermostat is set to the Heating mode if you want warm air and to the Cooling mode if you want the air conditioner to blow cold air.

Even though the configurations of each thermostat are unique, the owner's manual should be able to walk you through the programmable settings. 

• Check to see that the furnace switch is on so that it can supply power  to the HVAC system.- DIY Troubleshooting Tips for Thermostat Not Working

It's possible that your thermostat isn't working correctly because of an issue with your heating or air conditioning system rather than because it is broken or malfunctioning.

The furnace may have an issue if the thermostat is not functioning correctly. The furnace switch must be in the "on" position for the thermostat to work. You need to find the furnace to check that the switch turns on. A switch that appears to be a standard light switch will mount on the wall in the immediate vicinity. It regulates the flow of electricity to the furnace. If the switch for the furnace is tilted downward, which indicates that it is off, then turn it up, which suggests that it is on.

• Facilitate Air Flow- DIY Troubleshooting Tips for Thermostat Not Working

If your thermostat is malfunctioning, check the airflow in the room. The amount of airflow that enters and exits your heating and cooling system is a significant factor in overall performance. The air circulation provides the rooms in your house with the refreshingly cool air you desire. If the airflow is blocked, your heating, ventilation, and air conditioning system will have difficulty satisfying the thermostat, and the thermostat will not operate as it should. Therefore, check to see if any vents are obstructed or closed. After that, remove any impediments to ensure a constant flow of cool air in and hot air out (or vice versa in the winter).

If your thermostat is not functioning correctly, you should inspect the filters. The filters are in charge of collecting the dirt and dust particles that are produced. If the filters are not operating correctly, the thermostat will not be able to perform its intended functions.

Moreover, if the air filters are dirty and clogged with debris, it will be difficult for air to pass through them. It will not only makes the HVAC components work harder but also decreases the efficiency of the heating and cooling systems. The HVAC system may not function correctly because it cannot keep up with the temperature set on the thermostat.

If you cannot change the filters on your own or if the thermostat continues to malfunction after you have tried the solutions provided here, you may need to seek the assistance of a trained professional.

Why Is Your Thermostat Still Not Working?

Even after attempting all of the do-it-yourself troubleshooting tips, your thermostat still isn't functioning correctly. The following are some plausible causes:

• A Problem Occurred With the Thermostat's Programming- Why is your Thermostat still not Working?

In your home, one of the most important devices is the thermostat. It is possible to mess up the programming of a thermostat, which will result in problems with the device. Because of possibly incorrect programming, the homeowner's thermostat could be actively working against them. You may have the thermostat programmed for the wrong type of equipment, run on a pre-selected temperature schedule, set it for the incorrect mode, or have poor connections. s.

• A High Voltage Wire That Is Defective- Why is your Thermostat Still Not Working?

The high voltage wire is to blame for the thermostat not working correctly. The thermostat will not be able to send accurate signals to the heating, ventilation, and air conditioning system if there is a problem with the high-voltage wire. The problems with the thermostat may cause by a high-voltage wire that is either damaged, loose, or disconnected.

• Poor Quality Thermostat- Why is your Thermostat Still Not Working?

If your thermostat is not functioning correctly, a defective thermostat could be one of the reasons why. Like any other mechanical device, a faulty thermostat can result from random chance. Sometimes it just happens. A malfunctioning thermostat can result in several issues, including the inability to activate the cooling or heating functions, the failure to reach the desired temperature, the display of an error message, or incorrect temperature readings.

• There was no electricity; the furnace switch turned off, or the circuit breaker tripped. - Why is your Thermostat Still Not Working?

If the heating, ventilation, and air conditioning (HVAC) system cannot start up because it lacks power, you will be stuck with a thermostat that does not work. If you are having problems with your thermostat, check to see that the furnace switch turns on and that the circuit breaker for your HVAC system is in the correct position.

• Expended Fuse- Why is your Thermostat Still Not Working?

If your thermostat is not operating as it should, a blown fuse is one of the potential causes. Whenever a sudden electrical incident, such as a blown fuse, the thermostat cannot communicate with the rest of the system.

• Troubles with the heating or cooling system- Why does your Thermostat need to be fixed?

Most of the time, the problem with your thermostat is caused by an issue with your home's heating and cooling system. If your thermostat can never get the room temperature to where you want it, the problem may lie with your heating or air conditioning system. In particular, you might discover that your air conditioner is not turning on, leaking water, freezing, or blowing hot air. 

When the air conditioner or the furnace is not operating correctly, the thermostat may give the impression that it is not keeping up. A faulty blower motor, insufficient levels of refrigerant, or ductwork that has leaks are examples of common issues with an air conditioner or furnace that can lead to thermostat issues. 

Your furnace will not turn on, leak, or blow cold air. The worst-case scenario is that it will not turn on at all. Multiple factors are likely at play when you're having trouble with your thermostat. An HVAC professional is the only one who can correctly diagnose the underlying issue and provide a workable solution on a technical level.

In a related matter, if your system's emergency backup heat isn't working right, the thermostat will show an error message.

• Poor Flow of Air- Why is your Thermostat Still Not Working?

If the thermostat is not functioning correctly, one of the potential causes is an issue with the airflow. When an obstruction prevents air from circulating through the heating or cooling process, the HVAC system cannot keep up, and as a result, the thermostat will not achieve the temperature set. In addition, if there is a problem with the airflow, it may cause the heating and cooling systems to either overheat or freeze. It can restrict airflow, showing up as a reading on the thermostat if the filter is dirty, vents are blocked or closed, or the HVAC system is contaminated.

• A Defective Board of Control for the Thermostat- Why is your Thermostat Still Not Working?

If your thermostat is not functioning correctly, the problem may be with its control board. This board communicates with the HVAC system to ensure everything functions effectively and efficiently. The thermostat control board sends signals that activate and deactivate the heating and cooling functions. If there is a problem with the control board for the thermostat, you will notice that the thermostat is not working.

• Dead Batteries- Why is your Thermostat Still Not Working?

One of the typical reasons thermostats stop responding to user input is that the batteries have run out. If the batteries within the thermostat are dead, the device will no longer operate. After that, it will be necessary for you to change the batteries in the thermostat. If the thermostat is still not functioning correctly, you may need assistance from a trained professional.

• Poor Wirings- Why is your Thermostat Still Not Working?

There is a possibility that the faulty thermostat wiring is to blame for the malfunctioning thermostat. It is only possible for the thermostat to perform its intended functions if the wiring is fixed, loose, dirty, or disconnected in any way.

What To Check If Your Thermostat Isn't Changing The Temperature, And How To Fix It?

• Adjust the settings on the thermostat.- What Should I Do When the Thermostat Not Reaching the Set Temperature?

If the temperature in your home or place of business reaches the level you have selected on the thermostat, you may be dealing with a faulty unit. Your thermostat, like any other piece of electronic equipment, is susceptible to having hiccups in functionality from time to time.

Moreover, if the program it employs fails, it will not evaluate the temperatures appropriately or provide accurate readings. This guide may be helpful to you if you want to learn how to check the programming on your thermostat.

One more thing you can do is buy a thermometer explicitly designed for air conditioning. To put it to use, place it close to the thermostat and compare the readings' differences. After that, recalibrate the thermostat based on the readings from the thermometer and the instructions provided in the user manual for the thermostat.

• Wiring should redo the thermostat - What Should I Do When the Thermostat Not Reaching the Set Temperature?

If you recently purchased a new thermostat, but it has been giving you trouble since it was installed, the issue might be with the wiring in the wall. The majority of the time, this occurs after a do-it-yourself installation. Make use of the instruction manual to reattach all of the wires to the appropriate terminals.

On the other hand, there are times when corrosion and lint build up on the wiring, which prevents current from passing through. If you don't feel comfortable handling wires, you should have a professional inspect the problem with your thermostat and make the necessary repairs.

• Ensure the thermostat is clean- What Should I Do When the Thermostat Not Reaching the Set Temperature?

When the temperature in the room doesn't match what's set on the thermostat, it could be because dirt has built up in the parts inside.

An accumulation of dirt around the inner components may cause excessive heat and lead to inaccurate readings from the thermostat. To clean the thermostat, remove the faceplate and gently wipe away the dust and grime accumulated on it with a clean, soft brush. 

• Make Sure Your Old-Model Mechanical Thermostat Is Level- What Should I Do When the Thermostat Not Reaching Set Temperature?

f some of the internal components of an old round-dial thermostat aren't level, the thermostat won't function properly. The temperature on a mechanical thermostat is controlled by bimetal springs and a mercury switch that is oriented in a horizontal position within the device, in contrast to the digital thermostat that is most commonly used. Therefore, if the switch is tilted in any way, it will affect the accuracy.

To fix the broken thermostat, remove the faceplate from the device, locate the glass mercury tube, and then use a small level to bring it into proper alignment. You can replace the outdated and faulty thermostat with a newer, more efficient, modern model.

• If the thermostat is frozen, you will need to reset it- What Should I Do When the Thermostat Not Reaching the Set Temperature?

If there is a problem with the static electricity in the area surrounding your thermostat, the touch screen may freeze, and it will be unable to display any data updates.

When conditions are like these, it can be challenging to recognize when your electronic thermostat isn't achieving the desired temperature setting. The most effective course of action is to power down the device, wait at least ten seconds, and then power it back up again.

• Changing Out Your Outdated Thermostat- What Should I Do When Thermostat Not Reaching Set Temperature?

It is okay if the temperature in the room does not correspond to the setting on the thermostat or if the device you are using is too old.

An outdated thermostat might give accurate readings of the temperatures in your home, preventing the heating and cooling systems and the heat pump from operating incorrectly. And the heating and cooling unit will only be able to deliver the precise temperatures you want if you provide accurate information. Consider getting a new thermostat.

• Move Your Temperature Control Panel- What Should I Do When the Thermostat Not Reaching Set Temperature?

It could trick the temperature sensor into thinking there is more warm air in the house than there is if it is close to a window that gets a lot of direct sunlight or if it is near a fireplace, the kitchen, or a place where there is a lot of cooking going on. It indicates that your thermostat cannot sense the temperature of the interior of the building accurately.

If this is the case, you should collaborate with a licensed HVAC professional to move it. The specialist will assist you in locating the most suitable location for your relocation.

Why Thermostat Won’t Change Temperature: Causes, Troubleshooting & Fixes- Conclusion

In conclusion, a thermostat that won’t change temperature can be caused by several issues. The most common include dead batteries or power supply problems, power cycling the unit, blocked airflow, and incorrect settings. Troubleshooting usually involves changing batteries or cleaning the unit's sensors. 

If none of these remedies work, it is best to call an HVAC specialist. Thermostats are complex devices, and professional help may be necessary to diagnose the problem and ensure correct working conditions properly. With regular maintenance and timely repairs, homeowners can rest assured that their thermostats will continue functioning correctly for years to come.

Top 10 Thermostat Related Problems! Heat and AC!

Why Thermostat Won’t Change Temperature: Causes, Troubleshooting & Fixes- Recommended Reading

 Carrier Thermostat Reviews: Price Analysis, Buying Guide & Comparison

Troubleshooting Honeywell Thermostats: Top Most Common Problems with DIY Solutions

Thermostat Wiring Explained: How To Wire And Install A Thermostat

Frequently Asked Questions

How Much Does A Thermostat Replacement Cost?

The cost of replacing a home HVAC Thermostat in 2023 will vary based on several factors, including the type and model of the thermostat being replaced. Generally, a basic programmable thermostat for controlling the heating and cooling systems may range from $50 to $150 or more. High-end models may cost up to $400 or more. For example, wifi-enabled thermostats with touchscreens are likely to be at the higher end of the price range.

Installation costs can also add a lot to the total cost of replacing something. Homeowners sometimes choose to put in their new thermostats. But it's usually best to have a professional do the installation for the best performance and comfort. Professional installation costs could be anywhere from $50 to $200 or more, depending on factors like the installation's complexity.

When replacing an existing thermostat, homeowners should also consider any additional materials they may need. Thermostats sometimes require a power source, such as electricity or batteries, and wiring harnesses. There may also be other mounting hardware that is required for installation. All these items may add to the overall cost of replacement.

In summary, the cost of replacing a home HVAC Thermostat in 2023 ranges from about $50 for a basic model to several hundred dollars for advanced models, with professional installation fees included. Homeowners should carefully research options to determine which type best suits their needs and budget.

How To Keep Your Thermostat Working All Year Long

To maintain your thermostat in optimal condition throughout the year, here are some steps you can take:

1. Check and clean the vents regularly- How to Keep your Thermostat Working All Year Long

Dust and debris can quickly build up inside your HVAC system, which could cause the thermostat to malfunction. Make sure to check and clean them regularly for optimal performance.

2. Check the wiring and connections of your thermostat.- How to Keep your Thermostat Working All Year Long 

Loose connections or faulty wiring can cause erratic readings from your device and ultimately lead to inefficient heating or cooling. Have an HVAC technician inspect these components routinely for signs of wear or damage.

3. Inspect the temperature settings of your thermostat periodically.- How to Keep your Thermostat Working All Year Long

Thermostats set too high or low can result in inefficient heating or cooling. Make sure to reset your thermostat to the recommended temperature settings a few times a year for optimal performance.

4. Replace the batteries in your thermostat as needed- How to Keep your Thermostat Working All Year Long

Thermostats that run on batteries need new ones every so often, and failing to do this can cause the device to malfunction. Replace them when you notice any signs of wear or if they have been used for several years.

5. Have an HVAC technician perform routine maintenance on your system regularly.- How to Keep your Thermostat Working All Year Long

Thermostats are part of the more extensive HVAC system, and it is essential to ensure that all components function correctly. Regular check-ups and maintenance will ensure your system runs as efficiently as possible.

By following these steps, you can keep your thermostat working and efficient all year. Proper care and maintenance of your HVAC system are essential for optimal performance. Have an HVAC technician check on it regularly to maintain the best results.

Who Should You Call To Replace Your Thermostat At Home?

Replacing your thermostat at home can be a tricky task. To ensure the job is done correctly, it’s best to call an HVAC (Heating, Ventilation, and Air Conditioning) professional. An HVAC technician has the experience and knowledge necessary to install a new thermostat or replace an existing one with minimal disruption to your home. 

They will consider factors such as safety, efficiency, and compatibility when selecting the right thermostat for you, as well as any special considerations that may need to be taken into account depending on your specific circumstances. Once the work is complete, they will also provide helpful advice about temperature settings and energy-saving tips that can help reduce energy costs in the future.