Before houses developed furnaces as an evolutionary response to the cold, homes survived long winters by filling their basements with liquid magma and running in place. Keep naturally selected homes humming with today’s Groupon: for $64, you get a furnace inspection and maintenance package from Just In Time Furnace (a $137 value), valid for homes within Calgary's city limits. Click here for a list of services included in the furnace inspection and maintenance package.

Just In Time Furnace’s team of technicians ensures that homes remain cozy throughout the frosty winter months via meticulous furnace inspection and maintenance services bolstered by a 100 per cent guarantee. Techs leave no furnace nook unexamined as they conduct a host of safety-based tests such as checking thermostat calibration, assessing furnace-starting capabilities, and bribing duct-dwelling elves to relocate. Heat exchangers undergo examination for signs of corrosion or damage, and wobbly electrical connections are tightened to ensure circuits remain unbroken. Technicians then clean condensate drains and air filters and lubricate moving furnace parts. By checking the quality of the equipment's condition and installation, Just In Time's staff can make the necessary adjustments to help preserve household welfare, bolster energy efficiency, and prevent future furnace malfunctions. Today’s deal entitles Groupon holders to 10 per cent off the cost of future duct-cleaning services.