Does it cost more to keep turning heat on and off?

Does it cost more to keep turning heat on and off? Whether it costs more to keep turning heat on and off depends on how long you turn it off and how cold it gets. For short periods like few hours during day, turning heat off and on can cost more because furnace must work harder to reheat cold house and cold thermal mass like walls and furniture, using extra energy, and may cause pipes to freeze risk. For longer periods like 8 hours or more when away at work or overnight, setting back thermostat by 7 to 10 degrees can save 10 percent on heating bill annually, according to Department of Energy, because house loses less heat when cooler, so less energy needed overall. Modern programmable thermostats are designed for setback. Turning heat completely off in winter when outside below freezing is risky because pipes can freeze and cost thousands in damage, so better to set to at least 55 degrees. So for daily setback, it saves money, not costs more, but turning completely off and on frequently wastes energy and risks freeze.