How to Install a Mirror Defogger

We recently purchased a mirror online, and there are several important factors to consider when selecting one. Ideally, you want to choose a mirror that does not have a backing attached. In this case, the mirror we received does have a backing, so we removed it to ensure a proper connection to the back of the mirror. Once you have your mirror, the first step is to measure the available space behind it, as this will determine the size of the defogger you can use.

After measuring, we found that our mirror is just under 20 inches in diameter. However, due to the remaining cardboard or fiberboard backing, we have about 17.5 to 18 inches of usable space. This measurement indicates that our 15-inch defogger unit will fit perfectly. It’s important to note that while the defogger is 15 inches round, the power entry point is slightly off-center, positioned towards the top. This detail is crucial when mounting the defogger on the wall, as you want the power entry to be close to the location of the electrical box.

Now that we are ready to mount the defogger, we need to determine the appropriate height for the mirror. Since I am 6'1", I want to ensure that I can see myself in the mirror even when the rest of the room is foggy. Additionally, if there are shorter individuals in the household, such as a significant other or housemate, it’s essential to consider their height as well. I will mark the desired location for the mirror and take a measurement to locate the electrical box, which is about five and a half inches down from the top of the mirror.

Next, we need to account for the distance from the top of the liner to the screw hole for mounting the mirror, which is two inches. I will mark this measurement on the wall to indicate where we need to drill a hole for the screw. We have also marked the center location of the mirror, and I will measure seven and a half inches around it to ensure that the defogger is centered properly. It’s worth noting that part of the defogger will be positioned on the metal frame of the mirror, which may slightly affect heating in that area, but it should not be a significant issue over time.

To prepare the defogger for installation, I will peel back two inches of the adhesive backing. This step follows the earlier marking we made to locate the two-by-three electrical box in the wall, which guided our screw hole placement. As I align the defogger with the marks, I need to be cautious not to cut into the electrical coils, as doing so would damage the defogger and prevent it from functioning properly. After securing the initial couple of inches of the defogger, I can lift it up and gradually pull the adhesive backing while attaching it to the back of the mirror.

It’s essential to work slowly during this process to avoid trapping air bubbles, which can hinder the heating elements' connection with the mirror. If any air bubbles do form, you can push them out with your fingers. A clean mirror surface is vital for optimal adhesion, so I will ensure that the back of the mirror is thoroughly cleaned before proceeding. To facilitate trimming around the heating elements, I will mark a half-inch distance from them with a pencil, as cutting into the heating elements would ruin their functionality.

Once the defogger is properly positioned, it’s time to make the electrical connections. Before doing so, ensure that the breaker is turned off for safety. After making the necessary connections to the wall box, we can proceed to hang the mirror. This completes the installation of the mirror defogger, ensuring a fog-free reflection. Thank you for watching!