Extreme cold fronts tend to expose weaknesses in various home systems, and your home’s furnace is no exception. A furnace may run constantly during cold weather, costing you significant money. When this happens during a cold snap, it usually signals furnace efficiency problems that need attention rather than something homeowners should ignore.
Understanding Why the Problem Happens
Every house experiences heat loss during the winter season. Even if a house is insulated with the highest-grade materials on the market, the difference in heat loss when the outdoor temperature is 0°F is going to be roughly twice as much as it would be at 32°F. For your furnace, that means it likely has to run twice as often to sustain the same temperatures, which can cause high heating bills.
Note the outdoor temperature when your furnace is running constantly. If the problem appears in the 20-30°F range, then your furnace likely has serious problems. You may need a furnace repair or replacement. If the problem appears closer to 0°F, there is still a good chance it might require furnace maintenance. Even something as simple as replacing the filter can make a notable difference. You may see a 10% efficiency improvement, which might be enough to let your furnace rest a little bit on a bitterly cold day.
Insufficient Furnace Sizing
HVAC technicians size a furnace for a home’s specific air volume. This means the furnace’s capacity should be sufficient to heat that house at a target temperature range without constant cycling. If a furnace is undersized for a house, it will end up running more often because it can’t keep up with the demands during cold weather.
Sizing is a design choice during installation, and it varies in different parts of the country. Here in the Midwest, the target is usually to keep the furnace from constantly cycling even when the temperature is between -10°F and 10°F. Especially if your house has a relatively new furnace that’s cycling constantly during such cold weather, there is a good chance that its capacity is undersized relative to your home’s needs.
Insulation Issues
Anything you can do to slow the escape of heat from your house is a win. Poor overall insulation can lead to losses through the attic. Some older homes lack wall insulation, too. Worse, every decrease in outdoor temperature creates more pressure that drives more cold air infiltration into your house. In a home with insulation problems, even a well-tuned and brand-new furnace will struggle to keep up.
The good news is that you can do a few small things to improve the situation. Use expanding foam to plug gaps along the foundation. Consider a door sweep, too. This is a draft stopper or bottom seal that goes under a door to minimize the gap. Especially if you have unused rooms that get cold, this will make a difference.
Closed Vents and Cold-Air Returns
Vents and cold-air returns can close for a lot of reasons. Some people close them during the summer to avoid having cold air sink into the basement. However, they might forget to open the vents in the fall. Every fall, you should go around your house to verify that the vents and cold-air returns are open where you want them.
Returns and vents are also prone to closing for minor reasons. You could move a piece of furniture and accidentally jam a wooden leg into the lever. Even if it only partially closes the vent, that’s enough to cause trouble.
Also, check that vents and returns aren’t blocked. Something as simple as an end table disrupting airflow can be enough to reduce furnace efficiency and cause significant winter heating issues.
Potential Heating System Issues
A furnace of any age can have problems that make it operate worse in cold weather. You definitely want to start by making sure your furnace has a clean air filter. Also, make sure the air filter is the right type. Using a HEPA filter on a furnace that requires a simpler fiberglass filter could starve the burners of oxygen. This will make the furnace work harder.
Possible Mechanical Problems
Your furnace has several moving parts that can be problematic, especially without annual maintenance. Particularly, the blower motor can become less efficient with age. Our technicians always lubricate the blower motor’s moving parts to ensure efficient operation.
Similarly, fans and dampers in the ductwork can have trouble. A stuck damper, for example, may prevent heat from circulating properly. Likewise, failed fans might not transport heat where it needs to go. Good airflow ensures an accurate reading at the thermostat, and this should reduce your cycle’s run time. Lubrication usually fixes dampers, but some fans might require replacement.
Ductwork Leaks
Losses from ductwork are also troublesome. A few leaks in your home’s ducts can drop system efficiency by 20-30%. This is because leaks disrupt airflow efficiency and send heat to the wrong location. With the pressure in the system disrupted, less warm air gets where it needs to go on time.
Thermostat Issues
The placement and calibration of a thermostat can create problems. For example, a thermostat located closer to an outside wall might be convinced the temperature just isn’t hitting the target level. Consequently, the thermostat will signal the furnace to run more often. Moving the thermostat to a location that reflects the overall temperature of the house better can reduce long cycles.
You also want to be sure your thermostat is properly calibrated. Older thermostats can drift out of spec by 2-5°F, more than enough to send the wrong signal to the furnace. Our technicians can recalibrate or replace the thermostat to ensure it is correctly reading the temperature.
You may also want to consider adding sensors to the system. This allows the thermostat to sample temperatures from several rooms, giving the system a better picture of what the temperature actually is.
System Maintenance
A variety of problems can make your furnace less efficient. In gas-fired systems, carbon collects on both the burners and the pilot light sensor. Carbon buildup degrades system efficiency, leading to longer cycles.
A cracked heat exchanger can reduce efficiency and present a major safety issue. The heat exchanger is a component that transmits heat from the furnace to the vents without allowing gases through. If the heat exchanger has a crack, the heat will leak through it. This is inefficient, but it can also vent exhaust gases into the living area. Our technicians always inspect furnaces for common maintenance issues during annual fall checkups.
Call for Service You Can Trust
Duane Blanton Plumbing, Sewer, Heating & Cooling performs HVAC work for homeowners in Round Lake, IL, and the surrounding areas. With more than 35 years of industry experience, we know how to handle heating installation, maintenance, and repair issues thoroughly. We also offer 24/7 emergency service. Review our online ratings because you’ll be impressed by what our customers have to say about us.
If you’re worried about the furnace in your Round Lake home constantly running during cold weather, contact Duane Blanton Plumbing, Sewer, Heating & Cooling right away.
