During the warm months, home furnaces are not needed and therefore turned off. As the cold months roll in, people prepare their furnaces for use, which may include the cleaning of your heating unit. Turning on a furnace for the first time is not a very straightforward process. You have to activate the furnace, set the thermostat, and troubleshoot heating issues if needed. Read on to learn how to turn on the furnace.

Preparing for Setup

Read the instructions

There is usually a sticker on the front access panel that provides instructions for pilot igniting and other things related to basic heating system operation. The heater may not function efficiently without regular maintenance. Improper maintenance can lead to property damage, fires, explosions, and personal injury.

If your gas furnace does not have a label with instructions or find it hard to read the label, look for advice in the user manual. And if the user manual is not available, look for instructions online. Use the model number of the heater as keywords, and you will find instructions easily.

Not all heating systems are the same. Thus, to make it easy to locate various parts, use a diagram. You will find it online or in the user manual.

Related: How Long Do Furnaces Last

Inspect around the furnace

To learn how to turn on a furnace properly, pay attention to this step because it is essential. Heavy gases can sink to the floor, and later can be a cause of the disaster. Scrutinize the area and make sure there is no leak or water around the furnace.

If gas is detected, do not turn on appliances. Get out of the building as quickly as possible. For further instructions, contact your gas company.

If you find leaks, disconnect the supply of electricity to the furnace. Before you turn the switch on, repair leaking pipes and completely dry the area.

Do not turn the switch on if water covers any component of the furnace. To get the furnace inspected, you can consider calling a furnace technician.

If needed, resume power supply to the furnace

If you turn on the furnace for the first time after the warm months, you will have to find the fuse box or electrical panel. From there, restore power to the furnace. The fuse box or electrical panel may be in your utility room, basement, or garage. Make sure the breaker or furnace fuse is in the “On” position.

Remove the front panel

Use a screwdriver to unfasten the screws in the front panel. Remove the panel and then place the screws in a safe place. Now you will find the pilot light and the controls, such as the gas supply.

Lighting the Pilot of the Furnace

how to turn on pilotCheck pilot flame

To learn to turn on the furnace, you must check the flame. The Manual should show a picture of the pilot light. In general, the pilot light should not be dark yellow and not split into multiple flames. In addition, the flame should not waver or flicker.

If necessary, adjust the pilot

There is a screw on the pilot valve body. Turn the screw to adjust the pilot light. Open the access panel and then use a screwdriver to remove the pilot screw. To intensify the flame, turn the screw counterclockwise. To diminish the flame, turn the screw clockwise.

See the Manual learn how to adjust the screw. Remember, if you do this wrong, you could dangerously impact the performance of the pilot light.

The ideal intensity of the pilot light depends on the furnace. In general, the flame should be steady and between ½ and 2 inches tall.

If the condition of the pilot light remains questionable even after you have adjusted it, turn off the power and then relight the pilot.

For unit pilots, purge gas

Turn the switch to “Off.” The gas supply may be in the access panel or the control panel. Turn it to “Off” and then wait for 4 to 5 minutes.

Waiting is essential because you have to allow the gas to dissipate entirely. If it does not fully dissipate, it may lead to fire when you relight the pilot.

Now find the “Reset” button, which is usually close to the supply controls.

Light the igniter pilots

Hold a stem lighter in one hand and set the gas supply to “Pilot” with the other. Then press the “Reset” button and hold it for a few seconds. Allow the lighter flame to come to the opening. Release the “Reset” button after lighting the pilot. Then turn the gas supply switch to “On.”

Use a long stem lighter instead of a match. You can make a long stem lighter by rolling a piece of paper and igniting one end of it. If needed, repeat the lighting procedure. The flame should be steady and thick.

If you fail to light the pilot or if it does not stay lit, contact a furnace technician.

Activating the Furnace

Put the access panel back in place

Reattach the panel with a screwdriver. It is vital to reattach the panel properly because it may lead to problems when starting the furnace.

Switch the furnace on

In most furnaces, the position of the “On” switch is at eye level. 

Set the thermostat

Now your furnace has received power. Find the “Heat” setting and set the temperature. The furnace will automatically turn on when the temperature goes below the set level.

How to Turn on the Furnace – Conclusion

Turning on a furnace does not require much technical knowledge. Even if the unit malfunctions, you can troubleshoot the issue with the help of a manual. However, the ease of troubleshooting depends on the particular model you are using.