How to Turn Furnace On/Off

Just because a task is simple doesn’t make it intuitive. You can probably figure out on your own how to turn a furnace off and on, but that doesn’t mean you shouldn’t educate yourself on what the process entails first. After all, gas furnaces are not to be trifled with. You want to make sure you know how to safely operate one. It’s obvious why you would want to turn your furnace on, but there are many maintenance tasks and repairs that require you to turn it off, so you need to learn how to properly do that.

Turning On a Gas Furnace

how to turn on a gas furnace open the gas line
  1. Locate the switch or knob that displays three settings (On, Pilot, Off).
  2. Set the knob to off, then wait a few minutes in order to allow the gas to dissipate.
  3. Before proceeding, make sure the gas supply line valve is open (pictured).
  4. Now, turn the knob to the pilot.
  5. There should be a reset button, and you need to hold it down as you light the pilot. There is a chance the reset button is the knob. A match will work, but it’s easiest to use a lighter with a long arm. Once lit, do not ease off the reset button. You need to hold it for about a minute.
  6. Release the reset button and check the pilot to ensure it’s still lit.

How to Turn a Gas Furnace Off

Simply reverse engineer the previous process and set the control knob to off. Depending on the maintenance task you are trying to perform, it might not be a bad idea to cut power at the circuit breaker.

Turning an Electric Furnace Off and On

how to turn on an electric furnace light switch

This one should be super easy unless your furnace components or power supply are failing. Make sure the circuit breaker is set to on. Verify that the switch on the actual furnace is set to on. Then turn your furnace on by controlling it from the thermostat. Reverse the process on this in order to turn it off for maintenance and repairs.

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Related resources:
How to Check a Pilot Light
How to Light a Pilot Light
How to Reset a Furnace
Can You Bypass a Flame Sensor?

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