Why Is My Gas Bill So High? Common Causes and Expert Solutions

According to the Energy Information Administration, over half of all homes in the United States rely on natural gas to heat their home. And, while the average cost of gas was just under $700 per year in 2020, the cost has been trending up, with households spending an average of $964 in 2022. That works out to about $80 per month. So, you’re certainly not alone in asking, “Why is my gas bill so high?” In the next few sections, we’ll explore some of the potential causes for a high gas bill and share some changes you can make to lower your bill.

Aging Systems Can Lead to Higher Gas Bills

Max Veggeberg, CEO of Tetra, a heating and cooling company, explains that “an aging boiler, furnace, or water heater that can no longer keep up with the comfort demands of the home” is one of the most common causes for a high gas bill. Heating systems lose efficiency as they age, meaning an old furnace will need to work harder (and use more natural gas) to maintain the desired temperature than was necessary even a few years earlier. The same can be true for an outdated natural gas water heater. “Upgrading this may be an investment, but homeowners can see savings (and greater comfort in their homes) almost immediately,” Veggeberg tells Plane Grace.

If you’re going to purchase a new furnace, water heater, or other appliances, look for ones with an Energy Star seal that will offer greater efficiency and a lower gas cost per month. Another option is to consult with your HVAC company about the prospect of converting to an electric furnace.

Solution: Upgrade to a new furnace and/or water heater.

Older systems don’t just burn more gas—they can also struggle to distribute heat evenly, leaving some rooms colder than others. If you’ve noticed uneven heating or your system cycling on and off more frequently, it’s a sign it’s working overtime. Checking the age of your furnace (typically found on the unit’s label) can help you decide if it’s time for an upgrade. Most systems last 15-20 years, but efficiency drops significantly after a decade.

Inadequate Insulation Can Cause a Furnace to Work Harder Than Necessary

If your home doesn’t have enough insulation, then warm air can escape during the winter, making your furnace work harder to achieve your desired temperature. The increased runtime will require more fuel, leaving you with a higher natural gas bill. This problem can also lead to higher electric bills, so it is something just about everyone will want to address to decrease their utility costs.

“Most homeowners feel drafty windows and think they are the biggest cause of high energy bills or an uncomfortable home, but it’s more often low insulation levels. Windows only account for an average of 15 percent of a home’s surface area. Fixing insulation is also typically a much lower investment than fixing windows,” Veggeberg explains.

Solution: Hire a professional to perform a home energy audit to identify leaks or gaps in your insulation, and follow their recommendations to better insulate your home.

Beyond a professional audit, you can do a quick check yourself. On a windy day, hold a lit candle near windows, doors, or attic entrances to spot drafts. If the flame flickers, you’ve got an air leak. Adding weatherstripping or caulk can be a cheap fix, but for bigger issues like thin attic insulation, consider adding fiberglass batts or blown-in cellulose to keep heat where it belongs.

Higher Natural Gas Rates Can Lead to Higher Bills

Often, an increase in gas bill payment amounts boils down to the cost of natural gas. Unfortunately, natural gas prices can fluctuate and have been trending upwards for several reasons, including increased demand, international turmoil, weather disruptions, and more. If you signed up for a variable-rate plan with your fuel provider, then you’re going to be feeling the effects of all these occurrences.

Solution: Turn your thermostat down a few degrees, use alternative heating sources (such as a fireplace), or look for a long-term fixed-rate plan to eliminate surprise increases.

It’s worth calling your gas provider to review your plan. Fixed-rate plans can shield you from price spikes, especially during volatile market conditions. If you’re on a variable plan, compare rates from other providers in your area—deregulated markets often give you options. Also, layering up with sweaters or using a space heater for a single room can cut down on furnace use when it’s just a chilly evening.

Spikes in Usage Will Be Reflected in Higher Monthly Bills

If you have a gas furnace, seeing a gas bill increase during the cold, winter months is normal and generally not cause to rush to read your meter and ensure it isn’t malfunctioning. In this case, it’s also normal for your natural gas usage to decrease substantially during the spring and summer months when your gas furnace isn’t needed. Still, it can be a bit of a shock when you open a bill after your furnace kicked on during the first cold snap of the season.

Solution: While you cannot change the fact that you need heat during the winter, you can try to use less natural gas by setting your thermostat a few degrees lower than you typically do.

Tracking your usage patterns can help. Many utility companies offer online portals showing daily or hourly gas consumption. If you spot unusually high usage outside winter months, it might point to a water heater or gas stove issue. Small habits, like washing clothes in cold water or air-drying dishes, can also trim gas use year-round.

Neglecting Basic Furnace Maintenance Tasks Can Lead to Poor Efficiency

Even if your furnace and other natural gas appliances don’t need to be replaced, improper maintenance may be contributing to the natural gas price increase you’re seeing. Veggeberg explains, “Changing an air filter or wiping down dust and debris from your unit can improve your system efficiency by as much as 20 percent.”

Keep your gas dryer vent clean to help it operate more efficiently, and aim to replace your furnace filters regularly (every 2 months for fiberglass filters or every 6 months for pleated filters). It is also advisable to contact an HVAC company to perform a yearly tune-up for your system before the weather gets cold.

Solution: Keep up with regular system maintenance to ensure your appliances are operating efficiently.

A dirty filter doesn’t just choke your furnace—it can also raise indoor dust levels, which isn’t great for allergies. Set a calendar reminder to check filters monthly, especially during heavy heating seasons. If you’re not comfortable cleaning vents or inspecting burners yourself, a professional tune-up (usually $100-$200) can catch small issues before they become costly repairs.

Setting Your Thermostat Too High Can Lead to More Expensive Bills

If you’re searching for how to lower your gas bill, consider lowering your thermostat. The higher you have your thermostat set, the harder your furnace is going to have to work to heat the home and maintain the set temperature. Every time the furnace kicks on, it is consuming more gas, which could be why you’re seeing such high bills. According to the New Hampshire Department of Energy, lowering your thermostat by just one degree can save up to 3 percent on your heating costs.

Solution: Keep your home a few degrees cooler than you typically do.

Experiment with dropping the thermostat by 2-3 degrees at night or when you’re out. Wear socks or a cozy blanket to stay comfortable. If you’re hesitant to adjust manually, a programmable thermostat can automate setbacks, saving gas without you noticing the difference in comfort.

An Outdated Thermostat Could Be Increasing Usage Rates

The thermostat itself may even be to blame for higher than usual gas bills. If you have an older thermostat that isn’t functioning properly, it may be signaling for your furnace to turn on and off when it doesn’t need to. This can waste natural gas and lead to higher bills.

If you have an old thermostat, consider purchasing a smart thermostat to replace it. Not only will a new model be more accurate, but smart thermostats can help you save additional money. You can program them to lower the temperature in the home when you’re away at work and then to automatically heat it back up shortly before you return. You can even make adjustments to the schedules or the temperature inside the home from anywhere using a smartphone.

Solution: Upgrade to a new smart thermostat.

Smart thermostats, like Nest or Ecobee, can learn your habits and optimize heating schedules. Some even detect open windows or outdoor temperatures to adjust settings. Installation is often DIY-friendly, but if wiring looks tricky, a pro can set it up for $50-$100. Check for utility rebates, as many providers offer discounts on energy-saving upgrades.

A Gas Leak Could Lead to Higher Bills

If you have an unusually high gas bill, then it is also possible that you’re dealing with a gas leak. Gas leaks are uncommon, but not impossible. Knowing what a gas leak smells like can help cue you into a problem. If you smell something resembling rotten eggs, it can indicate that there is a gas leak. If you ever notice such a smell—or hear a hissing-like sound near any of your appliances that use natural gas—don’t stop to investigate. Evacuate all people and animals from the house and call 911. They will locate your gas shut-off valve and determine whether there is a gas leak in your home.

Solution: Call 911 immediately if you notice any potential signs of a gas leak.

Gas leaks are serious, but don’t panic. If you’re unsure about a smell, open windows to ventilate and avoid using electrical switches, which can spark. Regular inspections by your gas company (often free) can catch minor leaks early. Keep their emergency number handy, and never ignore a sudden spike in your bill without checking for other signs.

Final Thoughts

Opening a higher-than-expected natural gas bill is not a pleasant experience. While you, unfortunately, can’t do much about the current bill you’re looking at, implementing some of the changes and recommendations shared above can help keep future costs down. Consider keeping up with basic maintenance tasks, lowering the temperature on your thermostat, improving your home’s insulation, or contacting a professional to explore whether your outdated furnace should be replaced. A few changes can help offset rising natural gas supply rates.

One last tip: check if your state or utility offers energy assistance programs. Some provide low-income households with bill credits or free weatherization services, which can make a big difference. Small steps, like sealing gaps around doors or using insulated curtains, can also add up over time. Stay proactive, and your next bill might not sting as much.