Common Furnace Problems & Solutions: An Essential Guide

Furnace operating inside a contemporary home during winter, ensuring efficient heating and a comfortable indoor environment.

When winter hits Northern Idaho, a reliable furnace is essential to keep your home warm and comfortable. Unfortunately, cold weather can bring out some common furnace problems, leaving you and your family in the cold. Knowing how to troubleshoot these issues can make a huge difference, saving you time, stress, and money on repairs. Here’s a quick, easy-to-follow guide to troubleshooting common furnace problems, brought to you by Strobel Custom Heating and Air, your local experts in furnace repair and maintenance.

Understanding Common Furnace Issues

Furnace issues can be frustrating and costly, especially during the cold winter months. Understanding the common problems that can arise with your furnace can help you identify and address them before they become major issues. One frequent issue is a malfunctioning thermostat, which can cause your furnace to misread the temperature and either overheat or not heat at all. Another common problem is clogged filters. A clogged filter restricts airflow, making your furnace work harder and less efficiently, which can lead to higher energy bills and potential damage to the system.

A cracked heat exchanger is another serious issue that can occur. The heat exchanger separates the combustion process from the air that circulates through your home. If it cracks, it can allow dangerous gases like carbon monoxide to leak into your home, posing a significant health risk. Regular maintenance can help prevent these issues and ensure your furnace is functioning properly. By staying on top of these common furnace problems, you can keep your home warm and safe throughout the winter.

Furnace Won’t Turn On

One of the most frustrating issues homeowners face in winter is when the furnace simply won’t turn on. When this happens, the first thing to check is your thermostat. Make sure it’s set to “heat” and that the temperature is set higher than the current room temperature. Sometimes, a quick adjustment is all it takes to get things back on track.

If the thermostat seems fine, check the power supply to your gas furnace. A tripped circuit breaker or a blown fuse can easily stop your furnace from operating. Go to your electrical panel and see if the furnace’s breaker has been tripped—if so, reset it and see if that solves the issue. Additionally, some furnaces have a switch near the unit itself that can be accidentally turned off, so be sure it’s in the “on” position.

If you’ve checked these basics and the furnace still won’t start, it’s time to call a professional. Strobel Custom Heating and Air can diagnose the issue and get your furnace back up and running in no time.

Furnace Blowing Cold Air Instead of Heat

When your furnace starts blowing cold air instead of warm, it can be a major letdown. First, check the thermostat settings—sometimes, a simple switch to “heat” mode or adjusting the fan from “on” to “auto” can solve the problem. Setting the fan to “auto” ensures it only runs when the furnace is actively heating, rather than constantly blowing room-temperature air.

Another common cause of cold air is an unlit pilot light. For older furnaces with a standing pilot, you may need to relight it following the instructions in your furnace manual. Newer models may have electronic ignition, which could indicate an issue with the ignition system itself. The pilot light is crucial for the furnace functioning properly; variations such as flickering or abnormal colors could signal significant issues, including excessive carbon monoxide. Be cautious when attempting to relight the pilot, and if it doesn’t stay lit, it’s best to call a professional.

Strobel Custom Heating and Air can help with pilot light and ignition issues, ensuring your furnace is safely blowing warm air again.

Furnace Making Unusual Noises

Rattling, banging, squealing—if your furnace starts making strange noises, it’s trying to tell you something. Each type of sound usually points to a specific issue. Rattling or banging noises often indicate loose parts or debris in the system, while squealing or screeching could mean a worn-out blower belt.

If you hear a loud bang when the furnace starts, it could mean that there’s a delay in ignition, causing gas to build up and then ignite all at once. This is an issue you don’t want to ignore, as it could lead to more serious damage over time. Turn off the furnace and call a professional to inspect it.

Unusual noises are never a good sign, and they’re usually a signal that maintenance is overdue. Strobel Custom Heating and Air can inspect your furnace, find the source of the noise, and make any necessary repairs to keep your system running smoothly.

Weak or Inconsistent Airflow

Weak airflow or rooms that just won’t warm up can point to a few different issues. Start by checking your air filters. Dirty filters restrict airflow, making it harder for your furnace to distribute heat evenly throughout your home. Changing your filters every 1-3 months can make a noticeable difference in both airflow and efficiency.

Blocked vents and registers can also cause uneven heating. Walk through your home to make sure all vents are open and unobstructed. If weak airflow continues, the issue might lie with the blower motor or other internal components.

Strobel Custom Heating and Air can diagnose and resolve airflow issues, ensuring every room in your home stays warm. Regular maintenance can prevent these problems from developing in the first place, so it’s a smart idea to schedule a check-up.

Furnace Frequently Cycles On and Off Due to Malfunctioning Thermostat

Short cycling—when your furnace frequently turns on and off—is both inefficient and hard on your system. One common cause of short cycling is a clogged air filter, which restricts airflow and causes the system to overheat, prompting it to shut down to cool off. Replace the filter, and see if that helps.

Another potential culprit is a malfunctioning thermostat. A thermostat that’s poorly calibrated or located near a heat source (like a sunny window) might think the home is warmer than it is, causing the furnace to turn off prematurely. Try relocating the thermostat or adjusting its settings.

If these steps don’t resolve the issue, the problem could lie with the furnace’s internal components. Short cycling puts a lot of strain on the system and can lead to costly repairs. Strobel Custom Heating and Air can identify the cause of short cycling and get your furnace back to a regular heating cycle.

Pilot Light or Ignition Issues

A pilot light that won’t stay lit or issues with electronic ignition are common furnace problems, particularly with older models. A pilot light might go out due to drafts, dirt, or a faulty thermocouple, while an electronic ignition issue may stem from a malfunctioning sensor or control module. Additionally, problems with the natural gas supply can affect combustion and pose significant safety risks due to the flammable nature of natural gas.

If you have an older furnace with a standing pilot, try relighting it according to the manufacturer’s instructions. If it continues to go out or you notice other ignition issues, avoid repeated attempts to relight it and contact a professional. Ignition problems can pose a safety risk, especially when dealing with natural gas, so it’s best to leave this one to the experts.

Strobel Custom Heating and Air can safely handle ignition issues, ensuring your furnace runs safely and reliably throughout the winter.

Furnace Running Constantly

If your furnace seems to run nonstop, it could be a sign of several underlying issues. First, check your thermostat settings. If it’s set too high, the furnace may be struggling to reach an unattainable temperature. Adjusting the thermostat to a more moderate setting could help.

A furnace that runs continuously may also indicate a problem with the fan limit switch, which controls the blower. If the switch is faulty, it might keep the fan running even when the furnace isn’t actively heating. This issue can drive up your energy bills and put unnecessary wear on the system.

If adjusting the thermostat and checking for issues with the limit switch doesn’t resolve the problem, call Strobel Custom Heating and Air. Continuous operation can wear out your furnace and lead to expensive repairs, so addressing this issue early is crucial.

Troubleshooting common furnace problems in cold weather can help you maintain a warm, comfortable home even when temperatures drop. By knowing how to identify and address basic issues, you can save time, prevent expensive repairs, and extend the life of your furnace. From pilot light issues to weak airflow, many common furnace problems have simple solutions. However, some situations require a professional’s touch to keep your system safe and efficient.

For Northern Idaho homeowners, Strobel Custom Heating and Air is here to help with all your furnace repair and maintenance needs. Our team understands the demands of winter weather and is dedicated to providing top-notch service to keep your furnace running at its best. If you’re facing furnace issues you can’t resolve on your own, don’t hesitate to reach out to Strobel Custom Heating and Air for reliable, expert support.

Importance of Regular Maintenance

Regular maintenance is crucial to ensure your furnace is running efficiently and safely. A well-maintained furnace can help reduce energy bills, prevent costly repairs, and prolong the lifespan of your heating system. Scheduling annual furnace maintenance with a qualified furnace technician is highly recommended. During a maintenance visit, the technician will inspect and clean essential components such as the furnace filters, limit switch, and heat exchanger to ensure they are in good working condition.

Changing furnace filters regularly is one of the simplest yet most effective maintenance tasks. Clean filters improve airflow and efficiency, helping your furnace to heat your home more effectively. The limit switch, which controls the blower, is another critical component that needs regular inspection to prevent issues like the furnace running constantly. By investing in regular maintenance, you can ensure your heating system operates smoothly and efficiently, keeping your home comfortable during the cold weather.

Safety Considerations

Furnace safety is a top priority, especially when it comes to the heat exchanger and the overall heating and cooling system. A cracked heat exchanger can lead to carbon monoxide leaks, which can be deadly. It’s essential to ensure your heat exchanger is in good condition and functioning properly.

Heat Exchanger Safety

The heat exchanger is a critical component of your furnace, responsible for separating the warming flame from the air. A cracked heat exchanger can allow carbon monoxide to escape, posing a significant risk to your health and safety. If you suspect a cracked heat exchanger, it’s essential to contact a professional furnace technician immediately. Regular inspections can help detect any issues early, ensuring your furnace operates safely.

Heating and Cooling System Safety

Your heating and cooling system is designed to provide a comfortable and safe living environment. However, if not properly maintained, it can pose safety risks. Regular maintenance can help prevent issues such as a malfunctioning thermostat, clogged filters, and a cracked heat exchanger. It’s also essential to ensure your gas supply is turned off when not in use, and your furnace is installed and maintained by a qualified professional. By taking these precautions, you can ensure your heating system operates safely and efficiently, keeping your home warm and secure during the cold weather.