Common causes of high bills Your natural gas charges will vary from month to month, unless you are on equalized payments. Changes in natural gas consumption can depend on factors such as: Outside Temperature When wind chills are higher, your house gets cold faster and requires more energy to keep warm Your Home A furnace older than 10 years will use more gas than a high efficient model Energy-using habits and lifestyle appliances such as hot tubs, garage heaters and outdoor fireplaces The number of people visiting or living in your home The amount of time spent at home Poor insulation, old...