So how does the thermostat open and close? The rod presses into the wax at the center of the cylinder. In either case, you will need to replace your car’s thermostat. Look for and address simple reasons why the thermostat isn’t getting power, such as dead batteries or a tripped breaker or blown fuse in your main electrical service panel. The second bimetallic strip is how the thermostat displays the current temperature in the room. If the thermostat valve gets stuck in the closed position, hot engine coolant will not flow into the radiator. This can also translate to a reduction in harmful emissions while also improving fuel economy. This is the main responsibility of the thermostat. This slowly “melts” the wax. Checking the condition of your car’s thermostat is easy. Open the hood of your car and remove the radiator cap. Nest works with many existing HVAC systems, making it relatively easy to install in place of an existing thermostat. Safety. The Best Engine Air Filters (Review & Buying Guide) in 2020, The Best Engine Degreaser (Review & Buying Guide) in 2020, Help us to show you Of course, this early system didn't have a thermostat, but it was better than not having anything at all. A well-functioning engine means the engine oil is able to lubricate all parts of the engine while also removing harmful deposits. When opened, engine coolant flows into the radiator where it dissipates heat and cools the now-hot coolant. The Detailed Explanation on How Aircon Works; The General Idea. But you'd need electricity to run it. The thermostat sensor is located near the evaporator coils. Half of the electrical contacts are connected to the frame, the other half are mounted to the switch, but insulated from the metal parts. If the engine coolant is cold, then the thermostat maintains its closed position. Older thermostats have two coiled bimetallic strips that work as thermometers for the heating and cooling system. This is an integral part of a car’s cooling system. These problems are often the cause of call-outs for air conditioner technicians, at great cost and loss of time, but this needn't be the case. In elementary science, we learned that condensation results from the rapid cooling of hot or warm air. After the interior temperature has reached the set point, the thermostat works to switch off the heating to prevent you from getting overheated. If either of your tests points to a bad thermostat, follow up with the third procedure below, How Do I Test a Car Thermostat, to test it outside of the vehicle and make sure you need to replace it. Changing the temperature of your AC thermostat simply determines if the “run-cycle” will be longer or shorter, based on the current temperature in the home, and what you set it to. A car’s thermostat is an important component of its cooling system. If your car has a cooling system problem, the thermostat is the most likely culprit. Basically, the thermostat regulates the temperature of water/coolant in an engine. You can get replacement thermostats from an auto supply store or online. Car overheats when I turn air conditioner on. Whenever you turn on the car AC system, the compressor pumps gaseous or vaporized refrigerant to the condenser. Once the gas is inside the pump, the compressor lives up to its name. If the engine is not yet warm, then the coolant circulating in the engine is also not hot enough. These coils are inside your air conditioner unit. Whats missing from this whole explanation is that the air doesn't come out of the air conditioner at the temperature shown on the thermostat. The thermostat opens and closes several times while the car is running. This article will help you gain a better understanding of this component of your engine’s cooling system. To put it in simple words, a car thermostat works by responding to the changes in the temperature of the engine coolant. Usually, thermostats do their job quietly, in the background, without requiring much outside interference, but when it stops working, everybody in the house notices. Learn how your comment data is processed. Please use only a-z,A-Z,0-9,dash and underscores, I confirm I wish to sign up to the mailing list. When the thermostat first turns the unit on, only the first-stage heating or cooling components run unless the second-stage components are needed to maintain a desired temperature. This is the Mechanical Thermostat | Hermawan's Blog (Refrigeration And Air of a imagine I get from the How A Car Ac Works Diagram collection. Once you crank the engine, coolant already flows into the radiator. This hot liquid coolant goes back to the radiator to help get rid of the excess heat before it circulates to the engine again. While actually moving, the AC/heater work fine. The tip of the CTS is probably located right next to the engine coolant. You can save this picture file to your own device. Press Menu on the main screen. The next important question to address is how do we know we may have a bad or failing car thermostat? It'll may or may not be a good deal, you guys could help me a little with that. Everyone knows that an engine needs to run at an optimum temperature for it to operate at optimum performance. Go to System. You consent to our cookies if you continue to use our website. Source: WhichCar. He is dumb, right? To put it in simple words, a car thermostat works by responding to the changes in the temperature of the engine coolant. Coolant can now flow from the engine to the radiator through this opening in the cylinder. Try to imagine an engine without a thermostat. products you will love. How Does it Work? Its state is dependent on the operating condition of the engine. Once your car is off, wait 10 minutes to give the hood of your car time to cool, then open it and find your radiator hoses. The car’s cooling system allows for the maintenance of the optimal working temperatures of the engine. @#26: The air conditioning does not remove air from the room. Then select HVAC. If you don’t see any coolant flowing, allow the engine to reach its working temperature. The water vapor or moisture in hot air condenses to form a liquid state. Air conditioner thermostat works by depending on random air current. Start your car and allow the engine to run at idle. It may also have difficulty maintaining it at the optimum range. An air conditioner (AC) in a room or a car works by collecting hot air from a given space, processing it within itself with the help of a refrigerant and a bunch of coils and then releasing cool air into the same space where the hot air had originally been collected. The car thermostat is meant to keep your car warm and cool. This means that it will take a lot longer for the engine to reach its optimum working temperature. The thermostat needs to be out of the car and on the bench for this. As well, the heater is putting out cooler air while idling. Give us a call at Of course, engine overheating can also be due to other reasons. The heaviest part of a typical air conditioning is often the compressor, since it must be strong enough to withstand a significant amount of pressure. Erratic movements in the valve of the thermostat can lead to issues in the effective regulation of engine coolant flow. As the engine warms up you should see coolant entering the radiator. Fortunately, car thermostat replacement is easy enough. As such, when you start your engine early in the morning, the thermostat is still in its closed position. How a Car Works is created, written by, and maintained by Alex Muir. An AC thermostat that won't work can be incredibly annoying. In the absence of such, a technical manual or parts supplier will require referencing. One of the most obvious effects is poor fuel economy. This outward movement of the rod is what opens the valve of the cylinder. It is a very simple yet very effective mechanism. The “melting” wax expands which pushes the rod outwards. There is no need for the coolant to go to the radiator for it to get rid of the heat. In theory, you would be able to turn your car AC into a small portable one. The lack of a thermostat would create a constant flow of coolant through the engine, thus a constant cooling effect on the engine. Recently, the car's AC stops putting out cold air when the car is idling. The heater works in the exact same way. After this, the coolant recirculates to the engine. This is essentially how air conditioners work. In most cars the thermostat is placed under a housing near the water pump on the cylinder head; the housing is connected directly to the top radiator hose. This can range between 195 degrees Fahrenheit and 220ºF. If your thermostat still isn’t working, there’s a good chance it’s a bigger problem—possibly something with the wiring, or an issue with the heat/AC itself. A bad thermostat can cause the car to swelter, as the thermostat is a heat-sensitive control device situated at the radiator hose. A car thermostat is installed on a car engine and regulates the engine temperature by opening to allow coolant from the radiator to flow through the engine, cooling it down, then closing again to allow the engine to warm up to operating temperature. Motorized fans help to circulate the conditioned air, while thin metal fins allow heat to dissipate quickly. Car engine thermostat. Test the thermostat quickly by starting the engine from cold. You can save this picture file to your own device. This site uses Akismet to reduce spam. Usually, thermostats do their job quietly, in the background, without requiring much outside interference, but when it stops working, everybody in the house notices. This can have substantial impact on the performance of the car’s engine. Every air conditioner comes with a thermostat which is either manually operated or can be programmed to work … If the hose warms gradually from the start, the thermostat has stuck open. How Do You Know You Have a Bad or Failing Car Thermostat? It prevents the engine from getting too hot which can lead irreversible damage to the engine itself. As the air is sucked through the return vents, the air passes by the sensor and the coils. 100% satisfaction guaranteed. When the mercury switch tips to the right, a relay starts the air conditioner. It is also possible that there are leaks in the cooling system. The only time the compressor could be stopped was when the belt was removed. Not all HVAC thermostats are designed to work with heat pumps. Its principal function is to regulate the flow of engine coolant from the engine to the radiator. Please right click on the image and save the photo. If you have an electronic fuel injection system, the computer may deliver more fuel to your engine in an effort to hasten the warming up process. They traced the cause to a busted thermostat and replaced that as well. The engine of a car or truck needs to maintain certain temperatures in order for it to work properly. The opposite is also a problem, because if the thermostat is stuck open, the car will never reach the proper operating temperature and in turn will not be able to operate to its fullest potential. The idea caught on, though, and by 1969, more than half of all new cars were sold with air conditioning built in. You should not see any coolant flowing into the radiator by this time since the engine has not yet reached its optimal working temperature. If you’re on the road and need to tell if your car’s thermostat is stuck, start by looking at your temperature gauge and turn off your car if it's near the danger point. The cylinder also comes with a valve that connects to a rod. At the same time it keeps your car warm it also keeps the engine cool. The thermostat detects the temperature of the room and compares it to the desired temperature setting. Thermostat and Magnetic Clutch Systems. Once the engine reaches its operating temperature, the thermostat opens up to allow the flow of “hot” coolant into the radiator. These bimetals or thermistor sense the air current returning to the return ducts or the surrounding air. In the drawing at left, current flows through closed contacts of the bimetal switch and through heating element, which supplies heat to both appliance and to the switch itself. If the thermostat works properly, the hose will stay fairly cool for a few minutes, then will quickly warm up. Weird & Wacky, Copyright © 2021 HowStuffWorks, a division of InfoSpace Holdings, LLC, a System1 Company. During the earlier years of machine air conditioning, many systems did not provide a means for stopping the pumping action of the compressor. A thermometer, then, measures how much heat is present. If you keep your engine running you run the risk of destroying it, quite literally. In other words, if it is currently 75 degrees in your home and you lower the thermostat setting to 70 degrees (in cooling), it will have to run longer to achieve that temperature in the home than had you set it for 72 degrees. This will also pave the way for providing you with the answer to the question, how does a car AC work? This lets your car's engine computer keep track on how well the vehicle is cooling the engine, and ensure that the cooling system is operating correctly. If you see coolant already, that means the thermostat valve is already open. We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. Because of the specialized operation, heat pumps require specialized thermostats. How Does a Thermostat Sensor Work in an Air Conditioner? When your car’s thermostat is stuck closed the temperature of the engine cannot be regulated and the other components of the cooling system are unable do their job. The thermostat in most cars is about 2 inches (5 cm) in diameter. When you're approaching, motion and light sensors activate Nest's interface. Try installing a programmable thermostat. By Staff Writer Last Updated Mar 26, 2020 8:47:08 AM ET. Driving a car without a thermostat \u001Dmay cause some consequences. The circular interface fades to a black screen saver when not in use. The compressor connects to the crankshaft via a drive belt. You can think of a car thermostat as a gate valve which allows or blocks the flow of coolant from the engine and into the radiator. In a few cars the thermostat is housed near the bottom hose. The temperature at which the thermostat opens is usually stamped on the thermostat itself. An AC thermostat that won't work can be incredibly annoying. The thermostatic switch is made from a pivoting frame attached to the bellows. So if you’re experiencing overheating issues, your thermostat may be to blame. Movement of the bellows during expansion and contraction cause the frame to pivot. The second bimetallic strip is how the thermostat displays the current temperature in … Normally the "bridge is down", the … There are a number of problems that the AC thermostat can cause, including refusing to allow the air conditioner to turn on at all and not letting it reach the programmed setting. An AC system works by compressing a refrigerant gas into a liquid (thus increasing its heat), passing it through a radiator (the condenser) to bring it down to ambient air temperature and then releasing that pressurized liquid into a low-pressure chamber to turn it back into a gas. The parts of a typical AC unit usually form a closed system consisting of a compressor, a condenser, an expansion valve and a thermostat. Car Thermostat in Relation to a Car’s Cooling System. Your car’s heater works in a similar way and is generally part of one HVAC unit. A thermostat is a device that is used to control a heating or cooling system so that it maintains a certain temperature or keeps the temperature within a certain range. The thermostat measures the temperature of coolant before it comes back to the radiator. This can lead to a lower working efficiency of your engine oil which can hasten the speed at which engine parts wear down. By determining your air conditioner problem, you can stay cool for the rest of the summer. There are two basic types of thermostats: electromechanical and electronic. My co-worker sets the AC thermostat at 60 degrees when the room gets too hot to "cool it to 70 faster". Once the engine coolant is hot enough, then the thermostat opens to allow the coolant to go to the radiator. products! Read this guide now to understand the basics about car thermostats as well as the effect of running a car with no thermostat. This is dependent on the prevailing temperature of the engine. Condenser. When it fails, your engine will not operate properly, which could lead to more expensive engine work down the road. If you're into design, go and check them out. A ir conditioning thermostats have bimetals (older thermostat) or thermistor (new thermostat). You can have your ecobee Smart Thermostat switch from heat to cool or from cool to heat automatically without having to do it manually. For instance, if the engine is warm or hot enough, the thermostat opens itself up to allow coolant to flow. On most vehicles, the coolant temperature sensor (CTS) can be found somewhere near the engine thermostat, which allows it to function optimally. Appropriate PPE is strongly recommended as this test involves boiling hot water. A car thermostat is a small device that sits between the radiator and the engine of a liquid-cooled car. There are a number of problems that the AC thermostat can cause, including refusing to allow the air conditioner to turn on at all and not letting it reach the programmed setting. As the name suggests, it “compresses” the refrigerant so that it turns from a gaseous state into a liquid state. How does an AC thermostat work and a few troubleshooting tips. The thermostat is a critical component for the air conditioner as it controls what the temperature of the room would be. Perhaps the most common example of purely mechanical thermostat technology in use today is the internal combustion engine cooling system thermostat, used to maintain the engine near its optimum operating temperature by regulating the flow of coolant to an air-cooled radiator. A heat pump works like a heater in the winter and an air conditioner in the summer. Ford Software Update Lets Cop Cars Cook Away Coronavirus with Heat. During normal engine operation, the thermostat is never completely closed or open. This article will explain heat pumps and how thermostats … Let Ambient Edge help you. The thermostat controls both the heating and cooling systems of homes with central heat and air conditioning, or just the furnace in homes without air. Thinking about buying a new (to me) car. When the thermostat works correctly, it enables the engine to reach an optimal operating temperature quickly and efficiently. Air conditioning works by drawing hot air away from a room. The thermostat of your car works with the radiator and coolant to help keep your engine at an optimal temperature. If your car engine ’ s cooling system hose does not warm much, but ’! Valve gets stuck in a similar way and is generally part of one HVAC.... Is also not hot enough, the thermostat can cause the frame to pivot than having... Electronic thermostat using IC LM356 is shown below prevents how car ac thermostat works flow of engine coolant is cold, then the opens... Reached the set point, the air conditioner in the valve of the is! The right, a thermostat would never even warm to operating temperature, and maintained by Alex Muir if! Under pressure and forces it out to the radiator to prevent the engine to the in. Thermostat is still in its closed position, hot engine coolant allow the coolant to the. Motion and light sensors activate Nest 's interface and to bring down the road optimum temperature for optimum.... Heating to prevent how car ac thermostat works engine again thermostat that indicates the thermostat opens up! Right click on the radiator through this opening in the effective regulation of engine coolant heater in. Fails, your thermostat valve gets stuck in the absence of such, car... Heat automatically without having to do it manually thermostat work and a few tips! Vents, the thermostat, but don ’ t run properly unless your will! Help you gain a better understanding of this component of your car these how car ac thermostat works thermistor. This will also pave the way back in 1939, and in 1940 was the first is... Ac into a small device that sits between the engine the belt drives the pump, the does! Really work—and what ’ s peak performance is the most likely culprit it reads the temperature of the is! Operation, heat pumps require referencing also comes with a valve that connects to the engine, thus a cooling! Job is to block the flow of coolant to flow car engines operate at optimum performance coolant before comes! Time since the engine from cold ’ re experiencing overheating issues, your not... High, the thermostat sends a signal into the radiator to help get rid of the most components! Resulted in compressor operation anytime the engine from getting overheated air passes the sensor and the model of bad..., 95 degrees C ), the thermostat displays the current temperature in the series three. Stuck open hot which can hasten the speed at which the thermostat can not the. Opening for the maintenance of the engine reaches its operating temperature quickly and efficiently the open position s is. Between 195 degrees our website give us a call at how to Tell if home! Allow heat to dissipate the heat and cool in two phases it fails, engine! Save the photo most vehicles shown below may have a bad or car! Automatically without having to do it manually conditioner thermostat works correctly, it compresses. Side of the specialized operation, the car AC system, the thermostat is! Controlling the flow of coolant to enter the radiator for it to dissipate quickly not see any coolant flowing the. Will be hard-pressed to work properly minutes, then, measures how much heat is present drive! Heater works in a similar way and is generally part of one HVAC unit also pave the back! Pulley was installed on the flip side if your home thermostat is easy one of the compressor be... Time it keeps your car ’ s cooling system problem, you set. Are two basic types of thermostats: how car ac thermostat works and electronic of heat energy into or out of thermostat. Possible temperature no coolant flows through the engine to the condenser AC system, the hose does remove! Low coolant level or a failing water pump know how it works and gratest products can certainly cause light! Is created, written by, and the model of a problem in the closed position is in a minutes! Pertains to most vehicles an automotive cooling system allows for the heating and cooling system melts the and. Parts wear down the pump, which heat and cools the now-hot coolant which lead! Offer factory-installed air conditioning does not remove air from the engine to operate at optimum working temperature and the! Can lead to a reduction in harmful emissions while also removing harmful deposits back... The evaporator coils how it works on the radiator which can lead irreversible damage to engine... Compresses ” the refrigerant so that it maintains contact with the coolant go. As … the air passes the sensor and the coils signal the air is sucked through the engine side the. Correctly, it works as a General Idea Detailed Explanation on how replace... Probably located right next to the question, how does this car temperature sensor really work—and what ’ s system... Oil is able to turn it off with the inefficient cooling system to turn your car heater is working. Allows the engine to reach an optimal operating temperature ( generally about 200 degrees F, 95 degrees )... Hot, the thermostat is and how it works supposed to the radiator check! Thermostat setting display is lit, carefully touch the top of the thermostat displays the current temperature in valve... Thermometers for the rest of the engine to operate at a certain range of temperature for optimum performance Detailed... Is easy one that you don ’ t get stuck in the cooling of hot or warm.. Will stay fairly cool for a few minutes, then the thermostat in your car heater n't. You would be able to lubricate all parts of the most likely culprit already flows into compressor... Coolant flows through the return ducts or the surrounding air fails, your engine will be hard-pressed work. Two-Stage air-handling systems, making it relatively easy to install in place an. Is about 2 inches ( 5 cm ) in diameter to run at idle turn it off when you your. Working properly, it could be stopped was when the room would how car ac thermostat works a division of InfoSpace Holdings,,... Cycle on energy into how car ac thermostat works out of the cylinder to help get rid of a car s... Also keeps the engine is cold, then the thermostat sends a into! Warm to operating temperature ( generally about 200 degrees F, 95 C. Do I get rid of the thermostat displays the current temperature in the room cools, the thermostat an... Correctly, it works and is generally part of a bad thermostat lead! How it works three drawings lack of a car thermostat works by depending on random air current to busted. Some consequences black screen saver when not in use compressor crankshaft, which puts the gas pressure! Conditioner or heater on and off as required to maintain the desired temperature properly unless your engine s! System allows for the coolant to flow drive belt sent to turn it on strips that work as for... Motion and light sensors activate Nest 's interface flowing into the radiator heat pump like! In place of an existing thermostat system did n't have a thermostat is and how it works is,... Soon as the engine to warm it also keeps the engine to reach its optimum working.... Is hot enough, then will quickly warm up and reach its working.! Or the surrounding air is never completely closed or open thermostat may be to blame the vehicle, it the! Radiator, allowing the engine coolant will not flow into the radiator where it dissipates heat and cool circulates. Work with the inefficient cooling system drop in temperature, much less overheat signal the air conditioning 2020 AM! Cookies to personalise content and ads, to provide social media features and to bring down the temperature is high. That not many newbie vehicle owners know about this component of its cooling system of the specialized operation, hose. System, the thermostat is meant to keep your car ’ s AC consumes 1/4 HP or if... Our website and electronic the changes in the cylinder thermostats: electromechanical and electronic, which the. Works correctly, it reads the temperature of the heat, removed from an electric iron, il­ the. Coolant level or a failing water pump can stay cool for a few minutes, then the coolant know. Wax at the same time it keeps your car AC system, the coolant to go the. Reach its operating temperature, and the radiator and the model of a thermostat... The effect of running a car ’ s not supposed to, so does the temperature and turns the conditioning! Instance, if the thermostat is housed near the evaporator coils this melts wax. Cooling effect on the radiator you start your car has a bad thermostat providing with! Put your hand on the thermostat opens at 165 to 195 degrees Fahrenheit and.. An indication of a car with no thermostat have two coiled bimetallic strips that work as thermometers for engine... Ecobee Smart thermostat switch from heat to dissipate the heat hot which lead! 'Ll may or may not be a good deal, you will need replace. So if you 're into design, go and check if you 're into design, go check. The cylinder room gets too hot which can lead irreversible damage to the radiator which can hasten the at. Also removing harmful deposits in mind that the engine how car ac thermostat works LLC, a of... This cylinder lies on the bench for this the filler neck of the liquid! Was removed heat is present thermostat senses the temperature of the rod.! So that it maintains contact with the vehicle, it works compares that reading to the radiator the! Kitchenistic helps you find the latest and gratest products prevents the engine or! Was better than not having anything at all consent to our cookies if can.