How to Replace Knockouts

As a safety precaution and for protection against fire, all electrical panels and junction boxes are required to be fully secure. This means that if a knockout is removed and not used, it needs to be replaced with a knockout cover. A knockout cover is a small metal disc that snaps into the open hole left behind by the removed knockout.

Things You'll Need

• Knockout cover
• Hammer

Instructions

1. Measure the dimensions of the hole left behind by the removed knockout. Use those dimensions to find a compatible knockout cover at your local home improvement supply store.

2. Look at the knockout cover and you will see on the back of it there is a compression-type of ring. The ring snaps into the hole and secures the replacement to the box.

3. Insert one end of the knockout cover into the hole.

4. Push the other end until it snaps into place. If it is difficult to get the cover to snap in, give it a tap with a hammer.

Tips & Warnings

• Knockout covers come in various sizes, so always be sure you purchase the right size for the job.

• Don't install knockout covers on a junction box that contains hot wires. Always turn the circuit off before performing the job.