How to Install a Safety Switch on a Furnace Door

What You'll Need
Safety switch
Wire stripper
Circuit tester
Cover plate
Utility knife

Installing a safety switch on a furnace door is just so easy to do. All you need are proper materials, tools and right know-how on how to do it by yourself. Safety switches need replacement not just when it broke but also if it’s already worn out and defective. Remember that having efficient safety switch will also save you more on your electricity because the entire system functions well and fits just right. Now, if you are finally decided to install the safety switch on your own, all you have to do is to visit your favorite hardware or home improvements shop to get the switch for your furnace door. Once you have it, start preparing yourself and the furnace door for the exciting and challenging do-it-yourself job.

Step 1 – Prepare the Furnace Door

Ensure that the furnace door is clean and your working area is clutter-free. Next, turn the main power off where the circuit that you will be installing on is connected. You need to proceed with the main panel, and then turn off the breakers and ensure that the wires connecting to the furnace door and switch are shut off.  

However, if you are just replacing a broken switch, you need to get rid of the cover plate or face of the furnace door’s safety switch. Take away the 2 screws gripping on the switch inside the box. Unfasten the wires connected to the safety switch.

Step 2 – Install the Furnace Door’s Safety Switch

Arrange and organize the wires for the safety switch, with the use of a utility knife, cautiously cut the color white insulating coating placed on the power line. Remember to always be cautious not to scratch the inner wires. As soon as you can notice the inside wires, cut off the black wire located at the middle in order to make have 2 wire ends. Using a wire stripper, gently eliminate 1/2 inch to 3/4 inch (in length) of the plastic casing coming from every cut edge of the color black wire. Never alter or cut the green or white wires in any way.

After attaching the wire to the safety switch. Take note that the black wire from the breaker is the one needed to be attached with the brass screw located on top of the safety switch. Meanwhile, the other black, wire coming from the safety switch towards the furnace door, connects with the brass screw situated at the base of the safety switch.

Step 3 – Finalize the Safety Switch Instillation

Insert the safety switch inside the box. Secure it with screws, and always verify if all the wires are fastened firmly inside the safety box. Put in now the matching switch cover plate. Regulate the safety switch to the close position.

Go back to the breaker’s location then turn back on the power. Always double-check if the switch is working properly by means of having it open and close for several times. Check the circuit using a circuit tester, if available, for electric flow confirmation. Now, try to open your furnace door with the new safety switch and check the see its resilience and efficiency.