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Thermostats

Thermostat not working and showing an incorrect indoor temperature on the display
HVAC Systems, Repair, Thermostats

Thermostat Not Working: Common Causes and Fixes

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When homeowners call us frustrated, the issue can start with a thermostat not working the way it should. From our day-to-day work at C&R Services, we see how quickly a small control issue can disrupt comfort. Fortunately, many thermostat problems follow predictable patterns. Once you understand those patterns, the fixes become much clearer and far less stressful. Although the thermostat looks simple, it controls everything your heating and cooling system does. Because of that, a minor issue can feel like a major system failure. Before assuming the worst, it helps to walk through the most common causes step by step. In many cases, the fix is straightforward once the underlying cause is identified. Why a Thermostat Not Working Feels Like a System Breakdown When a thermostat not working properly sends incorrect signals, the system responds in confusing ways. Sometimes nothing happens at all. Other times, the system runs but delivers the wrong temperature. In our experience, this confusion leads many homeowners to suspect expensive equipment failures. However, the thermostat itself is often the real issue. That’s why starting with the control side saves time and unnecessary repairs. Thermostat Not Working Due to Power Issues One of the first things we check is power. A thermostat needs a steady power source to function correctly. Battery-powered models can stop working as batteries weaken, while hardwired thermostats may lose power due to tripped breakers or wiring issues. Because of that, a quick power check often reveals the problem right away. Thermostat Not Working Because of Mechanical Wear In older systems, the thermostat itself can also be part of the issue. Older mechanical thermostats rely on physical components that expand and contract with temperature changes, which can affect accuracy over time. For a clear explanation of how these thermostat designs work, ExplainThatStuff offers a helpful breakdown. Thermostat Not Working Because of Incorrect Settings Sometimes the issue isn’t hardware at all. Instead, it’s a simple setting problem. Mode selection matters. Heat, cool, auto, emergency heat, and auxiliary heat all behave differently. If settings don’t match the season, comfort suffers. For heat pump systems, confusion around backup heating is common. That’s why understanding what auxiliary heat is helps explain why systems sometimes behave unexpectedly during cold weather. Emergency heat, which is manually activated, can create similar confusion if selected accidentally. When a Thermostat Not Working Causes No Response at All If the system doesn’t start, the thermostat may not be sending a call for heating or cooling. In these cases, homeowners often assume the furnace isn’t turning on. While equipment issues do happen, thermostat signal failures are frequently responsible. Loose wires, damaged terminals, or failed internal sensors can all prevent startup. Addressing the control issue first avoids unnecessary component replacement. Thermostat Not Working and Warm Air Problems Another common complaint involves systems running but delivering the wrong temperature. In heating season, that usually means warm air never arrives. This scenario often overlaps with questions about why a heater seems to be blowing cold air. While mechanical causes exist, thermostat calibration errors or incorrect mode selection are frequently involved. When temperature readings drift, the thermostat may think the home is already warm. As a result, it short-cycles or fails to activate proper heating stages. Environmental Factors That Affect Thermostat Accuracy Placement matters more than most people realize. A thermostat near windows, exterior doors, or heat-producing appliances can misread room temperature. Sunlight exposure also skews readings. Because of that, systems may cycle incorrectly even when nothing is technically broken. During winter, heating systems run longer, which can make control issues more noticeable. As systems cycle more frequently, small thermostat inaccuracies tend to stand out faster, especially when a thermostat not working properly struggles to keep up with demand. The U.S. Department of Energy also shares general winter energy tips that explain why heating demand increases during colder months. Smart and Programmable Thermostat Issues Smart thermostats add efficiency but introduce new variables. Software updates, Wi-Fi interruptions, and compatibility issues can all interfere with operation. In the field, we see advanced features cause confusion when settings don’t align with how the system actually runs. Scheduling conflicts or incorrect learning behavior can mimic system failure. Although these thermostats offer real benefits, they still rely on correct setup. With proper configuration, they perform well, but when settings drift, comfort issues can show up quickly. When to Replace a Thermostat Instead of Repairing It Not every thermostat issue justifies repair. Older units lack modern accuracy and efficiency. Over time, internal sensors wear out and drift beyond reliable limits. If repairs repeat, replacement becomes the smarter choice. Modern thermostats improve comfort while reducing energy waste. In many cases, homeowners notice immediate improvements after upgrading. At C&R Services, we help homeowners choose thermostats that match their system type, usage habits, and comfort goals. Final Thoughts A thermostat not working rarely means disaster. More often, it signals a manageable control issue. With proper diagnosis, most problems resolve quickly and affordably. If uncertainty remains, professional evaluation prevents guesswork. At C&R Services, we take a diagnostic-first approach to protect both comfort and equipment life. If a thermostat not working continues to cause problems, a professional system evaluation can help identify whether the issue is control-related or system-related. If your thermostat continues acting up, contact us for expert help. We proudly serve homeowners across Tyler and East Texas, and we’re always ready to help restore comfort. Frequently Asked Questions About Thermostat Issues Below are a few quick answers we hear often from homeowners.

Technician testing a heat pump system during cold weather to check auxiliary heat performance
Heat Pumps, Heating, HVAC Systems, Maintenance, Thermostats

What Is Auxiliary Heat and How Does It Work?

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When homeowners ask “what is auxiliary heat,” it usually comes up on the first cold morning when their thermostat suddenly flashes “AUX.” You might wonder — is something wrong with my heat pump, or is this normal? At C&R Services, we’ve had plenty of calls that start with that same question. The short answer: it’s not always bad news. Auxiliary heat is simply your system’s backup plan for extreme weather, helping your home stay warm when your heat pump can’t keep up on its own. What Is Auxiliary Heat in a Heat Pump System? In simple terms, auxiliary heat (or “aux heat”) is a secondary heating source that kicks on automatically when your heat pump needs extra help. During mild weather, your heat pump transfers heat from outside air into your home. But when temperatures drop below a certain point — usually around 35°F to 40°F — that process becomes less efficient. That’s when auxiliary heat steps in. It usually uses electric resistance coils or, in some setups, a gas furnace to supply additional warmth. You might think of it like a car’s turbo boost — it’s not always running, but when it is, it gets the job done quickly. Many homeowners confuse auxiliary heat with emergency heat (EM heat) since both appear on thermostats and both provide backup warmth. The key difference is that EM heat must be turned on manually, while aux heat activates automatically when the system senses it needs extra power. For a deeper comparison, check out our post on what EM heat is and when you should use it — it explains when that mode should (and shouldn’t) be used. When Does Auxiliary Heat Turn On? Your thermostat and system controls decide when auxiliary heat activates. You might notice “AUX” appear on the display if: Outdoor temperatures are too cold for your heat pump to work efficiently Your thermostat raises the temperature several degrees at once The heat pump goes into defrost mode and needs temporary backup heat In most cases, auxiliary heat turns off automatically once your home reaches the set temperature. Still, if you see “AUX” on all the time, that can mean your system is struggling to keep up — or that something needs professional attention. (We’ve seen plenty of situations where a simple thermostat setting caused unnecessary aux use.) The Cost of Running Aux Heat Here’s the part homeowners often don’t love hearing: auxiliary heat uses more energy than regular heat pump operation. That’s because electric resistance coils draw a lot of power. If your system relies on auxiliary heat too often, your utility bills can climb fast. To keep costs down, make sure your home is properly insulated and sealed. Also, avoid large temperature swings on your thermostat. Gradual adjustments give your heat pump time to do most of the work before aux heat is needed. For more details on heat pump efficiency, the U.S. Department of Energy offers great guidance on how to optimize your system for different climates. How to Tell If Auxiliary Heat Is Working Properly One quick test is to check how the air feels. When auxiliary heat activates, supply air from your vents should feel noticeably warmer than during standard heat pump operation. If it feels cold or only slightly warm, there could be an issue with the heating elements or thermostat settings. At C&R Services, we test for this during regular maintenance. We measure current draw, inspect relays, and verify thermostat communication — small details that can make a big difference when temperatures drop. Preventing Overuse of Aux Heat 1. Regular MaintenanceA clean, tuned-up system performs better and doesn’t rely on backup heat as often. Dirty coils, clogged filters, or low refrigerant levels can all cause your heat pump to struggle. 2. Smart Thermostat SettingsModern thermostats can learn your habits and reduce unnecessary aux usage. (We’ve seen some homeowners cut energy use by 10–15% just by upgrading.) 3. Weather AwarenessWhen severe cold hits, it’s normal for auxiliary heat to run more often. But if you live in an area with frequent temperature dips — like parts of East Texas in January — it’s worth having a technician review your setup to ensure efficiency. If you’re looking for reliable seasonal advice and ways to save on heating costs, ENERGY STAR’s Heating and Cooling Guide has some solid, easy tips to follow. When to Call a Professional If your system runs on auxiliary heat constantly, blows cold air, or shows unusually high energy bills, it’s time for a service call. For more insight on that cold air issue, check out our post on why your heater might be blowing cold air — it breaks down the common causes and what to check before calling a pro. At C&R Services, we specialize in diagnosing all types of heat pump issues — including auxiliary heat problems — with accuracy and care. Whether you need repairs, maintenance, or a full system check, we’re here to help keep your home comfortable. FAQs About Auxiliary Heat Now that we’ve covered the basics, here are some common questions we hear about auxiliary heat during service calls. If you’ve ever wondered about aux heat and how it affects your comfort, the key takeaway is that it’s your system’s safety net — helpful when needed, but costly if overused. For peace of mind and optimal performance, schedule a heat pump inspection with C&R Services today. Contact C&R Services to learn more about our heat pump services or to book a professional tune-up that keeps your system running efficiently all winter long.

C&R Services - What Is EM Heat and When Should You Use It?
Heat Pumps, Heating, Thermostats

What Is EM Heat and When Should You Use It?

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If you’ve ever glanced at your thermostat and seen “EM Heat,” you’ve probably wondered what it actually means. At C&R Services, we get that question a lot—especially when the weather suddenly turns cold. So, what is EM heat in the first place? In simple terms, it’s your system’s backup heating mode—something that kicks in when your heat pump can’t pull enough warmth from the air outside. Now, that backup feature can be a lifesaver on a freezing morning, but it also uses more electricity than normal heating. Let’s go over how it works, when to use it, and how to keep it from driving up your energy bill. What Is EM Heat on a Thermostat? The term EM heat stands for emergency heat. It’s a backup heating mode on a heat pump system. When outdoor temperatures get too low or the main heat pump can’t operate efficiently, your thermostat can switch to emergency heat—usually powered by electric resistance coils or a gas furnace backup. So, what is emergency heat exactly? It’s the system’s way of saying, “Your heat pump needs help right now.” Instead of transferring warmth from outside air, emergency heat generates its own heat. That’s why it uses more energy and runs up higher electric bills. (Quick tip from the field—many homeowners accidentally turn on emergency heat manually, thinking it’ll heat their home faster. It will, but you’ll pay for it later when the power bill arrives.) How Emergency Heat Works When your heat pump can’t pull enough warmth from the air, the backup heating source steps in automatically. For most systems, this is electric resistance heating inside the air handler. Step 1: Heat Pump Struggles in Extreme Cold Heat pumps are efficient, but they rely on outdoor air for warmth. Once the air gets too cold, the system needs help. Step 2: EM Heat Activates At this point, emergency heat turns on to keep your indoor temperature stable. Your thermostat might display “AUX” or “EM Heat” to indicate the switch. If you’ve ever wondered how your system transitions between cooling and heating in the first place, check out our related article on how to switch your AC to heat. It’s a quick, step-by-step guide that explains thermostat modes and helps you avoid common seasonal mix-ups. Step 3: Higher Power Consumption Because resistance heating doesn’t transfer heat—it creates it—it’s much less efficient. During normal operation, your heat pump moves heat from outdoors into your home, which the U.S. Department of Energy notes is far more energy-efficient than generating heat directly. When EM heat turns on, however, the system switches to that less efficient electric resistance mode, which is why energy use climbs quickly. When Should You Use EM Heat? There are two main scenarios when it’s appropriate to switch to EM heat manually: Your outdoor unit isn’t working.If the heat pump freezes over, trips a breaker, or stops running altogether, emergency heat will keep your home warm until repairs are made. Your system can’t defrost itself.Sometimes, the outdoor coil ices up in extreme conditions. Switching to emergency heat can prevent further freezing while you call for service. Otherwise, let your thermostat handle it automatically. Most modern systems will engage auxiliary or emergency heat on their own when needed. (From experience—if your emergency heat runs constantly for days, something’s off. It might be a sensor, refrigerant charge, or airflow issue.) Why EM Heat Shouldn’t Run All the Time It’s tempting to think “more heat = better comfort,” but EM heat is only meant for short-term use. It’s like driving your car in first gear all week—technically possible, but inefficient and stressful on the system. If you find emergency heat staying on for long stretches, have your system checked. At C&R Services, we often find simple causes: a dirty filter, blocked outdoor coil, or faulty thermostat setting. Fixing these can save hundreds of dollars in wasted energy. For added protection, the U.S. Department of Energy recommends scheduling seasonal maintenance to keep your heat pump and backup systems balanced and efficient. Troubleshooting: What To Do If EM Heat Turns On Unexpectedly Step 1: Check Thermostat Settings Make sure it’s not accidentally set to emergency heat manually. Step 2: Inspect Airflow Replace dirty filters and clear vents. Restricted airflow makes your system work harder than necessary. Step 3: Call a Technician If EM heat keeps coming on without extreme weather, something inside the system needs attention. That’s where we come in. At C&R Services, our licensed technicians can test sensors, defrost cycles, and backup heating elements to ensure your system operates safely and efficiently. When to Call for Help If your heat pump is stuck in EM heat mode, or you’re unsure when to use it, don’t wait until the next cold front. Proper troubleshooting keeps your home comfortable and prevents costly wear on your system. Reach out to C&R Services—we handle heat pump services such as diagnostics, repair, and maintenance with precision and honesty. Final Thoughts So, what is EM heat? It’s your heat pump’s emergency backup for extreme conditions or system failures. While it’s there for safety and comfort, it’s not meant for everyday heating. Use it sparingly, and schedule regular maintenance to avoid relying on it too often. If you think your system is running on emergency heat more than it should, contact C&R Services today for expert inspection and support. We’re proud to serve homeowners across East Texas—keeping comfort steady through every season. Call us today at (903) 204-7571 to schedule your heat pump service or maintenance. FAQs Here are a few quick answers to the most common questions we get about EM heat and how to use it properly.

C&R Services - How to Switch Your AC to Heat: Step-by-Step Guide
Air Conditioning, Heating, Seasonal Tips, Thermostats

How to Switch Your AC to Heat: Step-by-Step Guide

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When the weather starts changing, it’s easy to forget that your HVAC system needs a little adjustment too. Every fall, we get calls from homeowners wondering how to switch from AC to heat without accidentally triggering an error code or blowing cold air. Trust us — it happens more often than you’d think. At C&R Services, we help families make the transition every year, and the good news is that it’s usually a simple process once you know what to check. Understanding How Your System Switches from AC to Heat Before you start flipping switches or pushing buttons, it helps to know what’s happening inside your system. When you switch from AC to heat, your thermostat signals your indoor and outdoor units to reverse their roles. Instead of pulling warm air out of your home, your heat pump or furnace begins generating warmth and distributing it through your ducts. (Quick tip—many homeowners forget to change their thermostat setting from Cool to Heat. It sounds obvious, but we’ve seen seasoned homeowners miss it after a long summer.) According to the U.S. Department of Energy, setting and programming your thermostat correctly can improve both comfort and efficiency. That means fewer surprises when temperatures swing overnight. Step 1: Set Your Thermostat to Heat Mode The first step in switching from AC to heat is updating your thermostat. Most modern thermostats have clearly labeled Cool, Heat, and Auto settings. If your system doesn’t respond immediately, don’t panic—it can take a minute for the system to recalibrate. For smart thermostats, double-check your app or schedule settings to make sure the system won’t automatically revert back to cooling mode. We’ve had more than one customer think their system was broken when it was just following a programmed schedule. Step 2: Adjust the Temperature Gradually When Going from AC to Heat When you move your system from AC to heat, avoid setting the temperature 10 degrees higher all at once. A gradual adjustment—say two or three degrees at a time—helps the system switch smoothly and reduces strain. This small change can extend the life of your components and prevent uneven heating across your home. Step 3: Listen and Observe After Switching from AC to Heat Once you’ve made the switch, stand near your vents and listen. You should hear a gentle hum or soft airflow within a few minutes. If you hear metallic clanks, buzzing, or smell burning dust, don’t worry right away—some odor is normal when the heating elements warm up for the first time in months. However, if it lingers, it’s worth calling a technician to take a look. At C&R Services, we always tell customers: trust your senses. If something sounds or smells off, there’s probably a reason. Step 4: Check Airflow and Filters When you go from AC to heat, airflow becomes even more important. Dirty or clogged filters restrict warm air and can trigger system shutdowns or short cycles. Replace your filters at the start of the season or at least every 90 days. For better indoor air quality and efficiency, most HVAC pros recommend using filters with a MERV-13 rating or higher—if your system can handle it. According to ASHRAE’s guidelines, airflow and system capacity should always be factored in when upgrading your filter. Step 5: Test Your Heat Pump or Furnace If your system includes a heat pump, switching from AC to heat is as simple as flipping the mode on your thermostat. The reversing valve changes direction automatically. But if you have a gas furnace, you’ll want to ensure your pilot light or ignition system is working correctly before you rely on it full-time. And if you need a clearer explanation of how a furnace generates heat, ignites, and pushes warm air through the home, our furnace guide walks through the entire process. We’ve had homeowners call in panic when they smell that first puff of dust burning off the coils—it’s totally normal. That smell usually disappears after a few minutes of running the heat. However, if your furnace won’t ignite or keeps blowing cold air, it’s time to schedule professional heating repair. When to Call a Professional If your thermostat doesn’t respond, your vents stay cold, or your breaker keeps tripping, it’s time to call for help. Sometimes, the problem is minor—like a loose wire or blocked intake. But it can also point to something more serious, such as a failed heat pump valve or dirty sensors. C&R Services handles all types of HVAC issues, and our team can make sure your system transitions safely and efficiently between seasons. Keep Your System Ready for Every Season Making the switch from AC to heat isn’t complicated, but it’s one of those small tasks that can make a big difference in comfort and reliability. Your cooling system worked hard all summer, so now’s the perfect time to shift focus to heating maintenance before cooler weather sets in. And when spring rolls around again, don’t forget to schedule your AC maintenance to keep both systems running at their best year-round. Contact C&R Services If you’re unsure how to switch your system from AC to heat or your furnace just won’t cooperate, our team can help. We offer fast, reliable HVAC repair and maintenance throughout East Texas. Call (903) 204-7571 or schedule your appointment online today. Stay comfortable through every season with C&R Services. Frequently Asked Questions Switching from AC to heat is a small seasonal task that saves big in comfort and peace of mind. And when in doubt, don’t hesitate to contact C&R Services. We’re your trusted HVAC experts in Tyler and throughout East Texas. We’re here to make sure your system transitions smoothly and keeps your home comfortable year-round. Still have questions about switching from AC to heat? Here are a few common ones we hear from homeowners every fall:

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