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Heat Pumps

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.

Outdoor mini split heat pump system installed beside a home — helps illustrate what size mini split you need.
Air Conditioning, Heat Pumps, Heating, HVAC Systems, Installation

What Size Mini Split Do I Need for My Home?

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If you’ve been wondering, “what size mini split do I need?”, you’re not alone. At C&R Services, we get this question all the time from homeowners looking to upgrade their comfort and cut energy costs. The truth is, choosing the right size mini split is about more than square footage—it’s about finding the perfect balance between efficiency, power, and comfort. And because mini splits use heat pump technology, they don’t just cool your home, they also provide efficient heating when the weather turns cold. As technicians, we’ve seen both ends of the spectrum: systems that barely cool the space and others so oversized they short-cycle all day. Neither is good for your comfort or your wallet. Why Sizing a Mini Split System Matters Before we get into sizing, it’s worth understanding what a mini split system actually is. In simple terms, it’s a type of heat pump that connects an outdoor unit to one or more indoor air handlers. Depending on the layout, mini splits can be ducted, ductless, or a mix of both, making them a flexible option for homes without traditional HVAC setups. When homeowners ask what size mini split they need, they’re really asking how much heating and cooling capacity fits their home’s needs. Mini splits are measured in BTUs (British Thermal Units)—the higher the number, the more power it delivers. But bigger isn’t always better. An oversized unit will cool or heat a room too quickly, shutting off before it can dehumidify properly. That leads to sticky air and uneven temperatures. On the flip side, an undersized unit struggles constantly, wasting energy while trying to keep up. (We’ve seen units in garages running nonstop in Texas summers—trust us, they don’t last long.) How to Calculate What Size Mini Split You Need So, what size mini split do you need for your space? The general rule of thumb is 20 BTUs per square foot of conditioned area. But this is just a starting point. Other factors like insulation, ceiling height, windows, and local climate can all affect your system’s true needs. Here’s a quick breakdown to help you estimate: Room Size (sq ft) Estimated BTU Capacity 150–300 6,000 BTU 300–500 9,000 BTU 500–1,000 12,000–18,000 BTU 1,000–1,500 18,000–24,000 BTU 1,500–2,000+ 24,000–36,000 BTU+ Still, this chart isn’t a replacement for a professional load calculation. If you’re serious about accuracy (and comfort), have a licensed HVAC technician run a Manual J calculation—the industry standard for properly sizing heating and cooling systems. You can learn more about what’s involved in a homeowner-friendly guide from Energy Vanguard. Factors That Affect Mini Split Sizing 1. Insulation and Air Leakage Poor insulation makes even a powerful unit work overtime. If your home leaks air through windows, doors, or duct gaps, your system’s performance will drop fast. 2. Ceiling Height Taller ceilings mean more air to condition. If you’ve got vaulted or open-concept spaces, go a bit higher in BTUs. 3. Sun Exposure Rooms that get a lot of sunlight—especially those facing west or south—tend to need extra cooling power depending on insulation and climate. 4. Local Climate In warmer states like Texas or Florida, cooling demands are much higher than in northern regions. For colder climates, heating performance and heat pump efficiency matter most. If you’re curious how mini splits compare to traditional systems, check out our post on what forced air heating is — it breaks down how conventional HVAC systems move air. (And if you live in a place like East Texas, where summers hit triple digits and winters can still surprise you, it’s best to size for both seasons.) Professional Help: How C&R Services Gets It Right At C&R Services, we don’t just guess when customers ask what size mini split they need. We measure, calculate, and verify—because every home is different. We look at room orientation, window types, insulation, and even your home’s construction materials. That’s what separates a precise installation from a rough estimate. We also guide homeowners through single-zone vs. multi-zone systems, helping you decide whether one indoor air handler will do or if your setup needs multiple units for even coverage. (For example, that upstairs bonus room that’s always hotter than the rest? We’ve all seen that one.) If you’re unsure, check out the Department of Energy’s guide to ductless heat pumps—it’s a great resource for understanding energy savings and system types. Lifestyle Considerations While sizing a mini split sounds technical, lifestyle plays a big role too. Do you cook often and heat up the kitchen? Do you prefer sleeping cold? Have pets that add body heat to a room? These details may sound small, but they help determine what size mini split you need to stay comfortable all year. Because most mini splits are heat pumps, they deliver comfort in every season — heating in winter and cooling in summer — all with impressive energy efficiency. And if you’re switching modes for the first time, our quick guide on how to switch your AC to heat walks you through it step by step. As techs, we’ve learned that comfort is personal. Some folks want steady cool air 24/7, while others just want to knock down the humidity. We tailor every recommendation to fit your habits, not just your square footage. Choosing the Right Mini Split Energy Efficiency and Rebates Always look for ENERGY STAR® certified systems. They’re more efficient, last longer, and can help you qualify for utility rebates or federal tax credits, depending on your location and program eligibility. To see what’s available in your area, check the ENERGY STAR Rebate Finder. Noise Levels and Design Modern mini splits are quiet—some are whisper-level—but placement still matters. Don’t mount the indoor air handler right above your bed or sofa if you’re sensitive to sound. Maintenance and Longevity Even the best-sized system won’t perform well without maintenance. Schedule yearly service to clean coils, check refrigerant, and inspect electrical components. A small tune-up goes a long way. Final Thoughts: What Size Mini Split Do I Need? If you’re

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.

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