Why Does My Furnace Smell Strange When I Turn It On?

November 4, 2026

A strange smell when your furnace starts can be unsettling, especially when Lincoln’s temperatures begin to drop. A light, dusty odor at the beginning of heating season may be temporary. Rotten egg smells, burning plastic, and persistent odors need a different response. 


Knowing the difference can help you protect your household and recognize when to schedule furnace repair in Lincoln, NE. 


Rotten Eggs or Sulfur: Leave Immediately 

A rotten egg or sulfur smell may indicate a natural gas leak. An odorant is added to natural gas to make leaks easier to detect. 


Leave the home immediately with everyone in your household. Do not adjust the thermostat, operate electrical switches, use your phone inside, or try to locate the leak. Once you are safely away, call 911 and your gas utility. Do not return until responders say it is safe. 


Black Hills Energy instructs customers to call 888-890-5554 from a safe location after calling 911. A suspected gas leak requires an emergency response before scheduling furnace repairs. 


A Light Dusty Smell: Often Temporary

Dust can collect on furnace components while the system sits unused. When you turn on the heat for the first time in months, that dust may create a brief burning odor. 


A mild smell that fades quickly can be normal at seasonal startups. However, an odor that persists, becomes stronger, or returns repeatedly should be checked. Do not assume every burning smell is dust simply because it is your first time using the furnace this fall. 


Burning Plastic or an Electrical Odor: Stop Using the Furnace 

A sharp electrical smell or burning plastic odor may point to overheating components or damaged wiring. These smells should not be treated as routine startup odors. 

Turn off the furnace if it is safe to do so and arrange professional service before using it again. Do not remove panels or attempt wiring repairs yourself. If you see smoke or flames, leave the home and call 911. 


A Musty Smell: Investigate Moisture 

Musty air coming through your vents may be associated with moisture or microbial growth around HVAC components, filters, or ductwork. The smell alone cannot confirm mold or identify its location. 


A recurring musty odor deserves an inspection to find the source. Covering it with air fresheners will not resolve an underlying moisture problem. 


No Smell Does Not Guarantee Safety 

Carbon monoxide is odorless and colorless. You cannot use your nose to determine whether your furnace is producing or leaking it. 

Maintain working carbon monoxide alarms near sleeping areas according to manufacturer instructions. If an alarm sounds, leave immediately and call 911 from outside. Headache, dizziness, nausea, or confusion can also be warning signs of exposure. 


Make Furnace Maintenance Part of Your Fall Routine 

Regular professional maintenance can help identify dirty components, airflow restrictions, and developing equipment problems. Check your filter regularly and replace it according to the manufacturer’s recommendations and your household’s needs. 


A furnace service visit can include checking burners, electrical components, the heat exchanger, and venting. Maintenance supports safer operation, but new warning signs still require attention between appointments. 


Frequently Asked Questions 

Is a furnace smell normal when I first turn it on? 

A mild, dusty smell that fades quickly can be normal. Strong, persistent, electrical, or rotten egg odors should not be dismissed as seasonal startup smells. 


Should I keep running my furnace to see if the smell disappears? 

Only a mild, clearly dusty startup odor may fade with brief operation. Stop using the furnace for electrical or burning plastic smells. If you suspect gas, leave immediately without adjusting equipment. 


Can I smell carbon monoxide? 

No, carbon monoxide has no smell. Working CO alarms are essential even when your furnace seems to operate normally. 


Schedule Furnace Repair in Lincoln, NE 

An unfamiliar furnace odor does not have to leave you guessing. Custom Cooling & Heating has served Lincoln and surrounding communities since 1982, providing heating repairs and maintenance. 


For nonemergency furnace concerns, call 402-489-9227 to schedule service and discuss the next steps for your home. 

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What Size HVAC System Does Your Home Actually Need?

October 5, 2026
A bigger furnace or air conditioner might sound like a safer choice, especially when you’re preparing for a Nebraska summer or winter. But equipment that is too large can cause comfort problems of its own. Equipment that is too small can struggle when temperatures reach their extremes. The right size depends on how much heating and cooling your home actually needs. If you’re planning an HVAC installation in Lincoln, NE, understanding how that need is calculated can help you make a more informed decision about your investment. Square Footage Is Only the Starting Point Two homes with the same square footage may need different HVAC systems. One might have well-insulated walls, newer windows, and plenty of shade. The other might have older windows, a large sun-facing living room, and rooms that are difficult to keep comfortable. A professional sizing assessment considers details such as: The home’s size and layout Insulation and air leakage Window size, type, and direction Ceiling heights Lincoln’s heating and cooling conditions The condition of your ductwork matters, too. Even equipment with the right capacity may struggle to keep every room comfortable if the ducts cannot deliver air effectively. The Problems Caused by an Oversized System An oversized air conditioner can cool the air near the thermostat quickly and shut off before it has run long enough to remove much moisture. Your home may reach the temperature you selected but still feel clammy. Short, frequent cycles can also mean more wear on the equipment. An oversized furnace may create noticeable swings between warm and cool instead of maintaining a steady temperature. The exact effects depend on the equipment and how the system is installed, but extra capacity does not automatically mean extra comfort. ENERGY STAR notes that oversized heating and cooling equipment can switch on and off rapidly, causing excess wear. A larger unit may also cost more upfront without solving the comfort issues that prompted the replacement. The Challenges of an Undersized System A system that is too small may have trouble meeting your home’s heating or cooling needs during very hot or cold weather. You might notice long run times and rooms that never seem to reach the thermostat setting. Longer run times alone do not prove a system is undersized. Some modern systems are designed to operate for extended periods at lower output. Dirty filters , duct problems, poor insulation, and other issues can also cause similar symptoms. That is why it helps to evaluate the whole home before assuming the equipment size is the problem. Check Your Home Before Choosing a System Your old HVAC system may not be the right size for your home today. New insulation, replacement windows, or a finished basement can change how much heating and cooling you need. Before selecting equipment, have a professional assess your home and discuss any rooms that are hard to keep comfortable. Ask how they chose the recommended size and whether your ductwork can support the new system. Those answers can help you choose an installation that fits your home and budget. Frequently Asked Questions Is a bigger HVAC system better for my home? No, a bigger HVAC system is not necessarily better. Oversized equipment can cycle frequently and may leave your home less comfortable, particularly when an air conditioner does not run long enough to remove enough humidity. Can I replace my old HVAC system with the same size? You can, but the old system’s size alone does not show what your home needs today. A fresh assessment is especially useful if you have had comfort problems or made changes to the house. What are signs that my HVAC system may be the wrong size? Frequent short cycles, uneven temperatures, persistent humidity, or difficulty reaching your thermostat setting can be signs of a sizing issue. Other problems can cause these symptoms, so a professional evaluation is the best next step. Plan Your HVAC Installation with Custom Cooling & Heating Choosing a new system means looking beyond the size of your current equipment. Custom Cooling & Heating has served Lincoln and the surrounding area since 1982 and can help you review your installation options.  To discuss HVAC installation in Lincoln, NE, explore our new installation services , request a free estimate , or call 402-489-9227 .

Signs Your HVAC System May Be Costing You More Than You Think

September 4, 2026
When utility bills begin to rise, it is natural to blame extreme temperatures or changing energy rates. However, part of the increase may be coming from an HVAC system that uses more energy than necessary. Many homeowners searching for heating and cooling in Lincoln, NE, do not realize how much efficiency has been lost until comfort problems or unusually high bills become difficult to ignore. Aging equipment, restricted airflow, leaking ducts, and missed maintenance can all make a system work harder to heat or cool the same space.  Custom Cooling & Heating has served Lincoln and the surrounding area since 1982. Our team can help identify the less obvious problems that affect your home’s comfort and energy use. Signs Your HVAC System May Be Wasting Energy An inefficient system does not always stop working completely. It may continue running while gradually using more energy and delivering less consistent comfort. Watch for signs such as: Utility bills rising without a clear change in household use Some rooms feeling warmer or colder than others Heating or cooling cycles that seem unusually long Frequent starts and stops Weak airflow from vents New noises, odors, or excess dust A system that struggles to reach the thermostat setting These warning signs can have several possible causes, which is why a professional evaluation is often the best way to find the source. Aging Equipment May Be Losing Efficiency Heating and cooling equipment experiences wear over time. Motors, electrical components, coils, and other parts may no longer operate as efficiently as they once did. Age alone does not automatically mean a system must be replaced. A well-maintained unit may continue providing dependable service, while a newer system with unresolved problems may still waste energy. However, rising bills, frequent repairs, uneven temperatures, and declining performance can indicate that it is time to compare HVAC repair and replacement . A technician can assess the system’s condition and help determine whether a repair could restore performance or a more efficient replacement may provide better long-term value. Airflow Problems Make the System Work Harder Your HVAC system relies on steady airflow to distribute conditioned air throughout the home. When that airflow is restricted, the equipment may need to run longer to reach the temperature set on the thermostat. A dirty filter is one of the most common causes of restricted airflow. Closed or blocked vents, buildup inside the system, blower motor problems, and poorly designed ductwork may also contribute. Check filters regularly and replace them based on the filter manufacturer’s directions and your home’s needs. If airflow remains weak after these basic checks, schedule professional service rather than continuing to lower or raise the thermostat. Leaky Ductwork Can Waste Conditioned Air The furnace or air conditioner may be operating correctly while the duct system loses heated or cooled air before it reaches your living spaces. Loose connections, gaps, holes, and missing insulation can allow conditioned air to escape into an attic, crawl space, basement, or garage. According to ENERGY STAR , a typical home can lose approximately 20% to 30% of the air moving through its duct system because of leaks, holes, and poorly connected ducts. Possible signs include uneven room temperatures, excessive dust, unusually high bills, or ducts located in unconditioned spaces that become very hot or cold. Proper sealing and insulation can improve comfort and reduce unnecessary system demand. Neglected Maintenance Allows Small Problems to Grow HVAC maintenance is designed to find developing issues before they cause a breakdown or a noticeable increase in operating costs. A system may continue running with dirty coils, worn parts, drainage problems, or incorrect settings, but it may use more energy in the process. During a maintenance visit, a technician can inspect the equipment, check electrical components, clean appropriate parts, evaluate airflow, and look for signs of wear. Custom Cooling & Heating offers maintenance memberships to help homeowners stay ahead of seasonal service needs and unexpected repairs. Find the Source of Rising Energy Bills A higher bill does not always mean you need a new furnace or air conditioner. Sometimes, replacing a filter, correcting an airflow issue, repairing a component, or sealing ductwork can make a meaningful difference. In other cases, aging or unreliable equipment may make replacement the more practical option. If you need help with heating and cooling in Lincoln, NE, Custom Cooling & Heating can evaluate your system and explain the available options. Contact our team or call 402-489-9227 to schedule a service. Frequently Asked Questions Why is my HVAC bill suddenly higher? Your HVAC bill may be higher because the system is using extra energy from weather, rate changes, airflow problems, duct leaks, equipment issues, or lost efficiency. How often should HVAC maintenance be scheduled? HVAC maintenance should usually be scheduled seasonally to keep the system efficient and catch small problems early. Does an old HVAC system always need to be replaced? No, an old HVAC system does not always need replacement. Its efficiency, repair history, condition, and comfort performance should guide the decision.