- +1 (919) 673-7667
- management@hvacicyhot.com
- Raleigh, NC 27606
A furnace that won’t heat your home on a cold Raleigh night is more than an inconvenience—it’s an emergency. Icy Hot Heating and Air Conditioning helps homeowners throughout Raleigh, Cary, and Apex diagnose furnace problems quickly and restore warmth when you need it most.
There’s nothing worse than waking up to a cold house in the middle of winter. You check the thermostat, and it’s set correctly, but your furnace just isn’t producing heat. Before you panic and assume you need a complete replacement, it’s important to understand what might be causing the problem and when you actually need professional help.
Most furnace heating issues fall into two categories: simple fixes you can handle yourself and complex problems that require a licensed HVAC technician. At Icy Hot Heating and Air Conditioning, we’ve responded to countless emergency furnace repair calls throughout the Raleigh area, and we’ve learned that many homeowners can avoid service calls by performing a few basic checks. However, knowing when to call for professional heating repair in Raleigh can prevent small issues from becoming expensive disasters.
Let’s explore the common reasons furnaces stop heating, what you can check yourself, and when it’s time to call Icy Hot Heating and Air Conditioning for expert furnace repair.
Understanding why your furnace isn’t producing heat helps you determine whether you’re facing a minor issue or a serious problem requiring professional attention.
The thermostat is often the culprit when your furnace won’t heat. If it’s not communicating properly with your furnace, the system won’t know when to turn on or how much heat to produce.
Common thermostat problems include incorrect settings (set to “cool” instead of “heat”), dead batteries in battery-powered models, poor calibration causing inaccurate temperature readings, and wiring issues that prevent proper communication. In older homes throughout Raleigh and Cary, we frequently find outdated thermostats that simply need replacement.
Smart thermostats add another layer of complexity. While they offer convenience and energy savings, they can malfunction due to Wi-Fi connectivity issues, software glitches, or incorrect programming. Sometimes a simple reset resolves the problem, but other times the unit needs reconfiguration or replacement.
A dirty air filter is the most common cause of reduced heating performance and the easiest problem to fix yourself.
Your furnace pulls air through the filter before heating it. When the filter becomes clogged with dust, pet hair, and debris, airflow becomes restricted. This restriction forces the furnace to work harder and can trigger safety switches that shut down the system to prevent overheating.
In Raleigh’s climate, where we experience high pollen counts in spring and fall, filters clog faster than in many other regions. During heating season, homeowners in Apex and surrounding areas should check filters monthly and replace them every 1-3 months depending on usage and home conditions.
Signs your filter is the problem include weak airflow from vents, the furnace running constantly but not heating effectively, and the system shutting off prematurely. A severely clogged filter can also damage the blower motor over time, turning a $20 filter replacement into a $400+ motor repair.
Gas furnaces rely on proper ignition to create heat, and problems with the pilot light or electronic ignition system will prevent your furnace from heating entirely.
Older furnaces with standing pilot lights can experience flame outages due to drafts, thermocouple failures, or gas supply issues. You might notice the pilot light is out or burning yellow instead of blue, indicating incomplete combustion or gas mixture problems.
Modern furnaces use electronic ignition systems that eliminate the standing pilot light for better efficiency. These systems can fail due to a faulty ignition control module, a cracked hot surface ignitor, or sensor problems. When electronic ignition fails, you’ll typically hear the furnace attempting to start but never producing heat.
Safety is paramount with gas furnaces. If you smell gas or suspect an ignition problem, don’t attempt DIY repairs. Turn off the gas supply to your furnace and call Icy Hot Heating and Air Conditioning immediately. Gas leaks and improper combustion can create dangerous carbon monoxide situations.
The blower motor pushes heated air through your ductwork and into your home. When it malfunctions, your furnace might be producing heat, but that heat isn’t reaching your living spaces.
Common blower problems include worn motor bearings that cause squealing or grinding noises, capacitor failures that prevent the motor from starting, belt issues in belt-driven systems, and electrical problems that interrupt power to the motor.
You might notice the furnace fires up and the burners ignite, but little or no air flows from your vents. Alternatively, the blower might run continuously without cycling off, or you might hear unusual noises coming from the furnace cabinet.
The flame sensor is a safety device in gas furnaces that confirms the burners have ignited properly before allowing gas to continue flowing.
When the sensor malfunctions or becomes dirty, it may not detect the flame even when combustion is occurring properly. This causes the furnace to shut off after just a few seconds of operation—a condition called “short cycling.” You’ll hear the furnace fire up, maybe feel a brief puff of warm air, then everything shuts down.
Flame sensors accumulate buildup from combustion byproducts over time. Sometimes a simple cleaning resolves the issue, but sensors can also fail electronically and require replacement. This is a common problem we address during routine maintenance visits throughout the Triangle area.
Hidden ductwork issues can make it seem like your furnace isn’t heating when it’s actually working fine.
Leaky or disconnected ducts allow heated air to escape into attics, crawl spaces, or wall cavities instead of reaching your living areas. In older Raleigh homes, we frequently find duct tape (which ironically fails on ducts) deteriorating and connections separating.
Blocked or crushed ducts prevent airflow to specific rooms or areas. This might happen if insulation has been installed improperly, if storage items are blocking vents, or if pests have built nests in ductwork.
Undersized or poorly designed duct systems create airflow restrictions that reduce heating efficiency. Some rooms might stay cold while others overheat, and your energy bills will be higher than necessary.
Before scheduling a service call with Icy Hot Heating and Air Conditioning, you can perform several simple checks that might resolve the problem or at least help our technicians diagnose the issue more quickly.
Start with the basics because thermostat issues cause many unnecessary service calls.
Verify these settings:
Replace thermostat batteries if your model uses them. Even if the display is lit, weak batteries can cause communication problems with your furnace.
Try a thermostat reset by removing it from the wall plate for 30 seconds, then reinstalling it. For smart thermostats, consult the manufacturer’s instructions for proper reset procedures.
Locating your air filter is the first step. It’s typically found in one of these locations: inside the furnace cabinet where the return duct connects, in a return air grille on a wall or ceiling, or in a filter rack between the return duct and furnace.
Remove the filter and hold it up to a light. If you can’t see light passing through, it’s too dirty and needs replacement. Even if it doesn’t look completely clogged, replacing a filter that’s been in place for 3+ months is good practice.
Choose the right replacement filter. Check the size printed on the frame of your old filter (such as 16x25x1) and the MERV rating. Don’t exceed the MERV rating recommended by your furnace manufacturer—higher-rated filters restrict airflow and can damage your system.
Install the new filter correctly with the arrow on the frame pointing toward the furnace (in the direction of airflow). An improperly installed filter provides no filtration and can get sucked into the blower assembly.
Check the power switch near your furnace that looks like a regular light switch. It’s often on a wall near the unit or on the furnace cabinet itself. Make sure it’s in the “on” position. These switches sometimes get accidentally turned off when people are storing items near the furnace.
Inspect your electrical panel for tripped breakers. Furnaces typically have a dedicated 15-20 amp circuit. If you find a tripped breaker, reset it once. If it trips again immediately, you have an electrical problem that requires professional diagnosis.
For gas furnaces, ensure the gas valve is open. The valve handle should be parallel to the gas line. If it’s perpendicular, the gas is shut off. However, if you find the gas mysteriously shut off, don’t simply turn it back on—call a professional to investigate why it was closed.
If you have an older gas furnace with a visible pilot light or burners you can see through an observation window, look at the flame characteristics.
A healthy flame should be:
Warning signs include:
Never attempt to relight a pilot repeatedly if it won’t stay lit. This could indicate a gas valve problem, thermocouple failure, or dangerous ventilation issue. After one or two attempts, call Icy Hot Heating and Air Conditioning for professional service in Raleigh, Cary, or Apex.
Your furnace’s sounds tell a story about its operational health.
Normal sounds include:
Concerning sounds include:
Any unusual sound warrants attention. Document what you hear and when it occurs so you can describe it accurately when you call for service.
Some furnace problems are beyond DIY troubleshooting and require professional expertise. Knowing when to call prevents dangerous situations and avoids making problems worse.
Call Icy Hot Heating and Air Conditioning’s 24/7 emergency service immediately if you experience:
Gas odors anywhere in your home. Natural gas has a distinctive “rotten egg” smell added for safety. If you smell gas, evacuate everyone from the house, don’t use any electrical switches or create any flames, and call 911 and your gas company from outside. Once the situation is safe, call us to inspect and repair your furnace.
Carbon monoxide detector alarms. Carbon monoxide is an odorless, colorless, deadly gas produced by incomplete combustion. If your CO detector sounds, treat it as a life-threatening emergency. Evacuate immediately, call 911, and don’t return until authorities clear your home.
Visible smoke or fire coming from the furnace. Shut off power at the breaker, evacuate your home, call 911, then contact us once the fire department gives clearance.
Complete heating loss during freezing weather. When temperatures drop into the 20s and 30s in Raleigh, going without heat puts your pipes at risk of freezing and bursting. This qualifies as an emergency requiring immediate attention, especially for homes with elderly residents, young children, or anyone with health conditions.
Schedule same-day or next-day service for:
Furnace short cycling where the system turns on and off every few minutes. This indicates a safety control is tripping, and continued operation can damage components or create safety hazards.
No heat production when you’ve already checked the thermostat, filter, power, and gas supply. At this point, you’ve exhausted the DIY checklist and need professional diagnosis.
Unusual smells like burning dust (normal for the first use of the season but concerning if persistent), burning plastic or electrical odors, or musty smells indicating potential mold in ductwork.
Rapidly increasing energy bills without corresponding increases in usage. A furnace working inefficiently will run longer cycles and consume more energy to maintain temperature.
Inconsistent heating where some rooms are comfortable but others stay cold. This might indicate ductwork problems, zoning issues, or a furnace that’s losing capacity.
Sometimes repair isn’t the best option. If your furnace is over 15 years old and facing repairs costing more than half the price of a new heating installation, replacement might be more economical.
Consider replacement when:
Icy Hot Heating and Air Conditioning provides honest assessments. We’ll never push unnecessary replacements, but we will explain your options clearly so you can make an informed decision. Modern high-efficiency furnaces can reduce heating costs by 20-40% compared to units installed 15+ years ago.
HVAC technicians bring expertise that goes far beyond DIY troubleshooting.
We have specialized tools including combustion analyzers to measure furnace efficiency and safety, multimeters to test electrical components accurately, manometers to check gas pressure, and inspection cameras to examine hard-to-reach areas.
We understand complex systems. Furnaces involve gas supply, electrical controls, mechanical components, and safety devices all working together. Misdiagnosing the problem can lead to expensive parts replacements that don’t fix the issue.
We ensure safety. Gas furnaces involve combustible fuel, carbon monoxide risks, and high-voltage electricity. Professional service protects your family and your property.
We warranty our work. When Icy Hot Heating and Air Conditioning repairs your furnace, you get a warranty on both parts and labor. DIY repairs offer no such protection.
Regular maintenance and smart usage habits dramatically reduce the likelihood of furnace failures and extend your system’s lifespan.
Preventive maintenance is the best investment you can make in your heating system’s longevity and reliability.
Icy Hot Heating and Air Conditioning’s maintenance packages include:
Schedule maintenance in early fall before heating season begins. This timing ensures your furnace is ready when you need it and allows you to schedule repairs conveniently rather than during an emergency.
The cost of maintenance typically pays for itself through improved efficiency, fewer repairs, and extended equipment life. Homeowners with maintenance plans also receive priority scheduling and discounts on repairs.
Consistent filter changes are the single most important thing you can do to maintain your furnace between professional visits.
Standard 1-inch filters should be changed monthly during heating season if you have pets, someone with allergies, or heavy system use. Every 2-3 months is acceptable for minimal use in homes without pets or air quality concerns.
Thicker 4-5 inch filters in media cabinets can last 6-12 months depending on conditions. However, check them every few months to ensure they haven’t clogged prematurely.
Set calendar reminders on your phone or mark filter changes on a physical calendar. Many homeowners throughout Raleigh and Cary forget this simple task until their furnace stops working efficiently.
Your furnace needs breathing room for safety and proper operation.
Maintain at least 30 inches of clearance on all sides of your furnace. Don’t store boxes, holiday decorations, cleaning supplies, or other items in the furnace room that restrict airflow or access.
Never store flammable materials like gasoline, paint, solvents, or propane tanks near your furnace. The pilot light or electric ignitor can ignite vapors from these materials.
Keep combustion air vents clear. Furnaces need fresh air for proper combustion. If your furnace has dedicated combustion air pipes, ensure they’re not blocked by insulation, bird nests, or debris.
Poor indoor air quality affects both your health and your HVAC system.
Watch for signs like excessive dust accumulation on surfaces, musty or stale odors, increased allergy or asthma symptoms, and condensation on windows indicating humidity problems.
Consider upgrades such as whole-home humidifiers to combat Raleigh’s dry winter air, air purifiers to remove particles and allergens, UV lights to control mold and bacteria growth, and upgraded filtration systems for better particle capture.
These improvements not only make your home more comfortable but also reduce strain on your furnace by maintaining cleaner indoor air.
Modern thermostats offer features that improve comfort while reducing energy costs and system wear.
Programmable thermostats allow you to automatically lower temperatures when you’re sleeping or away from home. Reducing your temperature by 7-10 degrees for 8 hours daily can save up to 10% on heating costs.
Smart thermostats learn your schedule and adjust automatically. They provide usage reports, remote control via smartphone, and alerts when problems occur. Many utility companies offer rebates on smart thermostat purchases.
Proper thermostat placement matters. Thermostats should be on interior walls away from direct sunlight, drafts, doorways, and heat sources. Poor placement causes inaccurate readings that make your furnace work harder than necessary.
Keep records of your furnace’s installation date, maintenance history, and repairs.
Most gas furnaces last 15-20 years with proper maintenance, while electric furnaces can last 20-30 years. As your system approaches these milestones, plan financially for replacement and watch for signs of declining performance.
Document problems and repairs in a simple notebook or phone app. This history helps technicians diagnose recurring issues and helps you make informed decisions about repair versus replacement.
Register your equipment with the manufacturer to ensure you receive safety notices and maintain warranty coverage. Keep warranty documentation accessible so you know what’s covered if problems arise.
Don’t let a furnace problem leave you cold. Whether you need routine maintenance, emergency repairs, or expert advice on replacement options, Icy Hot Heating and Air Conditioning is here to help homeowners throughout Raleigh, Cary, Apex, and the surrounding Triangle area. Our experienced technicians provide honest assessments, quality repairs, and reliable service you can trust. Contact us today to schedule maintenance or request emergency furnace repair service.
Icy Hot Heating and Air Conditioning Inc provides expert HVAC services, including installation, repair, and maintenance, ensuring year-round comfort.
HVAC License#: L.34356
