How Hard Can It Be To Install A Dimmer?


If you’re somewhat mechanically inclined, this doesn’t seem like an insurmountable task. There are, however, a few items that need to be considered before you want to try this on your own.

Rule 1 of every electrical project is to turn off the power.  This means turning off not just the power to the switch that you are planning to replace, but also all the power. While it’s not too common, it is possible to run into more than one live circuit in a box, especially a ganged box with more than one switch.

The next step is to check if you have purchased the correct dimmer. The differences are not just in colour and aesthetics. What type of light source are you trying to dim, incandescent, fluorescent, LED, line voltage or low voltage? Most of these can be dimmed; however, you need to determine if the lamps are dimmable and whether the dimmer is compatible with the type of lamp and fixture. Even if you have determined that the lighting is LED, there is more than one type of dimmer depending on what LED fixture you have.

Ok, now you have the dimmer and lighting matched. What size of dimmer do you need? Dimmers are typically rated by their wattage. This means adding up the wattage and buying a dimmer large enough to handle the load. You also have to be careful how many dimmers you place side by side in a ganged box. The rating may have to be reduced if more than one dimmer is placed in a box.

Well, we’re almost there. Power is off and you have the right dimmer. Let’s pull out the old switch and make the swap. Is the lighting controlled from more than one location? If so, you may need to purchase a three-way dimmer. The wiring here is a bit more complicated as there are three wires rather than two. If you mix up the wiring, the two switches will not operate properly.

There is one last item that you need to consider, whether the new dimmer will actually fit in the box. Not all boxes are the same depth. Particularly in condominiums, the walls are not built with standard 2×4 studs and the boxes are shallower to accommodate. Between the reduced depth and the number of wires in the box, it can often be difficult if not impossible to fit in your new dimmer.

Well, if you have worked out all those details, put the plate back on, turn on the power and admire your handiwork. I know the satisfaction that can come from watching the lights beautifully dim after you’ve finished your project. Grab a glass of wine and enjoy the ambience.

Of course, if this all sounds too complicated, please feel free to call us.

Yours in electrical safety and simplicity,

Mark Marmer

Signature Electric.