How To Wire a Furnace Shut-Off Switch

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A furnace shut-off or disconnect switch helps you maintain safety when working on your heating unit. In this blog post, Inland Empire Comfort, trusted experts in furnace repair in Riverside, CA, will show you how to wire a furnace shut-off switch. Keep reading to learn more about connecting a shuff-off switch to furnace units.

What You’ll Need During Installation of Furnace Shut-Off Switch

Ensure you have the following items before you start following the furnace safety switch wiring instructions:

• Screwdrivers
• Sheathed cable bushing
• Single-pole 15-amp circuit breaker
• 14-gauge sheathed cable
• Switch wiring box
• Cable stripper
• Long-nose pliers
• Single-pole switch
• Wire nuts

Now, let’s talk about how to wire a furnace shut-off switch. 

Steps for Wiring a Furnace Shut-Off Switch

Once you have all the necessary items for the furnace emergency shut-off wiring, follow the steps below.

Step 1

Switch the main circuit breaker in the service panel off. Remove the cover screws before opening the panel. 

Step 2

Ensure the switch on your new circuit breaker is in the off position. Next, hook the circuit breaker back on the metal tab of the service panel and press it into place. 

Step 3

Use a screwdriver and pliers to detach a knock-out plug from the service panel. Then, install a sheathed cable bushing before inserting the cable into the service panel via the bushing. 

Step 4

Strip a three-eighth inch of insulation from the black and white cable wires. Connect the bare ground to the ground bus together with other ground wires and tighten the screw. 

Likewise, connect the white wire to the neutral bus alongside other white wires. Connect the black wire to your new circuit breaker terminal before tightening the screw. 

Step 5

Install your switch wiring box near the furnace wiring box before routing the cable from the panel to the switch wiring box. Next, route another cable from the switch wiring box to the furnace wiring box. Peel six inches of sheathing off the cable ends and connect them to the switch wiring box. 

Step 6

Strip a three-quarter inch of insulation from the wires in the switch wiring box. Twirl the two ground wires together and leave one end free. Bend the free end 180 degrees before placing it clockwise around the ground terminal of the green switch. 

Step 7

Twirl the two white wires as you did with the ground wires before screwing on a wire nut. Bend the ends of black wires 180 degrees and place them clockwise around the switch terminals. Using the two supplied screws, install your switch in the wiring box and screw the cover plate onto the switch box. 

Contact Inland Empire Comfort for High-Quality Heating and Cooling Services in Riverside, CA!

We hope this DIY wiring guide for the furnace shut-off switch has been helpful. If you need further information on how to wire a furnace shut-off switch or want help determining how old your AC unit is, talk to Inland Empire Comfort. Call (951) 789-3238 to book your appointment in Riverside, CA!