Many homeowners choose a dimmer switch based on how it looks and the features it has. And those things are important.
But the most important part is making sure the switch will work in the setup you have. After all, what good is a dimmer switch that looks great but doesn’t work? So in this article, we’re going to show you the 3 steps to choosing a dimmer switch that works.
Once you’ve got all that sorted, then we’ll briefly go over some of the style and features available for your dimming needs.
Let’s get started.
Step 1: Match your bulbs with a compatible type of switch
In the old days of incandescent bulbs, pretty much any bulb was compatible with any dimmer. Unfortunately, that’s not the case anymore.
Incompatible bulb and dimmer combos create problems like:
- Flickering – Bulbs flashing on and off
- Dropout – The bulb only dims down to a certain point and then turns off
- Staircasing – The bulb dims in abrupt steps rather than smoothly and continuously
- Dead travel – When you slide the dimmer but the light doesn’t change brightness
- Pop-on – When the bulb is turned on, it goes to full brightness instead of remembering the dimmer level
So you need to choose a dimmer that works with the bulbs you have or are planning on buying. Here are your most common dimmer switch options, based on the type of lights you want to dim. Also, for best results, don’t mix different types of bulbs on the same switch (for example, pairing LEDs with incandescents).
If you want to dim incandescent or halogen light bulbs, you can use either a universal dimmer switch or a incandescent/halogen-only switch. Universal dimmer switches are more expensive, but also work with many LED and CFL bulbs. So if you ever change your bulbs to more energy efficient options, you won’t also have to replace the dimmer switch.
LEDs and CFLs
First of all, make sure that the LED and CFL bulbs you buy are dimmable. Not all of them are. Next, look for a universal dimmer-one that specifically says it will work with LEDs and CFLs.
But don’t stop there. Check the list of compatible bulbs that the manufacturer provides. CFLs and LEDs have drivers (small chips) in them that must be compatible with the dimmer switch you purchase.
You can often go to the dimmer manufacturer’s website and find the bulbs that have been tested to work with that dimmer.
Low-voltage lights like under-cabinet lighting, track lighting and LED strip can also be dimmed. But they require special, low-voltage dimmers. And there are 2 types of low-voltage dimmers:
- Magnetic low voltage (MLV) dimmer
- Electronic low voltage (ELV) dimmer
The kind you need depends on the type of low-voltage lighting you have. If you’re not sure, consult the manufacturer of your lights or a licensed electrician.
If you have fluorescent lights (not to be confused with compact fluorescent lights, or CFLs), you need a specialty dimmer that controls only dimmable fluorescent lights. Again, it’s a good idea to check with the manufacturer’s compatibility list, if available.
Step 2: Calculate the size dimmer switch you need
Before you purchase a switch, you need to know the maximum load (measured in watts) of the switch.
You see, dimmer switches are rated to handle a certain amount of electrical power (watts) and this is called the maximum load. Using a dimmer for a load above its maximum can cause the switch to get really hot and become a fire danger.
Most common dimmer switches are rated for 600-700 watts for incandescent bulbs and up to 150 watts for LED and CFL bulbs. But there are high-capacity switches that have 1000 or 1500-watt maximums.
Here’s the simple formula to calculate the size dimmer switch you need:
Wattage of bulb x number of bulbs = total wattage on switch
If you have a single bulb on the switch you’re replacing, it’s simply the wattage of that one bulb. But if your new dimmer switch will control a whole set of bulbs, there’s a little more math involved.
For example, let’s say you have 7, 65-watt bulbs in your kitchen that are all controlled by a single switch. The load on that switch is 455 watts (7×65=455). So you need a switch with a maximum load above 455 watts.
A note about maximum loads on dimmers
The maximum load on dimmer switches usually depends on how many other switches are installed in the same electrical box.
For example, a switch can have a 600-watt maximum when it’s the only switch in the electrical box. But when it’s installed next to another switch it may be rated for 500 watts. And 400 watts when installed in between 2 other switches.
The manufacturer’s instructions should tell you the maximum load for each situation.
Example dimmer switches installed next to each other. Photo credit: Reuben Saltzman, StarTribune
Step 3: Match the dimmer switch type to your wiring setup
You need to purchase the type of dimmer that works with the wiring setup you have. And there are 3 main types of wiring setups for switches:
- Single-pole dimming
- 3-way dimmer
- Multi-location dimmer
You need a single-pole dimmer if there’s only one switch that controls the light or group of lights you’ll be dimming.
If you have multiple light switches for a light or group of lights, a 3-way dimmer is the easiest option. You’ll be able to dim the lights from the dimmer switch and the other switch(es) will let you turn the lights on and off.
If you have multiple light switches and want to be able to dim from all of them, you want a multi-location dimmer and companion or “accessory” dimmers.
For each installation, you need a single multi-location dimmer, which acts as the master, and 1 or more companion dimmers.
Now, choose your style and features
Once you have the technical specs of the dimmer you need, you can get to the fun part of choosing the style and features you want your dimmer switch to have.
Here’s a picture showing the main styles of light dimmers.
Types of dimmer switches available. Photo source.
All of dimmer styles basically fall into one of the following categories:
These are the most basic types of dimmer switches. They only control the brightness of the lights. To turn your lights off, you must turn the brightness all the way down.
Examples: Slide and rotary dimmers (pictured above)
Pro: Simple to use. The slider or dimmer is large and easy to change.
Con: Constant fiddling. Since you have to turn the dial all the way down to turn the lights off, every time you turn them back on, you must find your preferred lighting level.
Dimming controls with on/off switches
The second style of dimmer switches has a dimmer control as well as a dedicated on/off switch.
Examples: Rocker dimmers, toggle dimmers and slide dimmers with on/off button (pictured above)
Pro: Lets you keep your preferred brightness level even when turning the light off.
Con: The slider to control the brightness of the lights is often much smaller and more difficult to finely tune.
More advanced dimmer switches come with these common features:
Save your favorite settings
Want to save several different light brightness settings? Some dimmers, like this Lutron C.L Maestro switch, let you do just that. You tap the button to cycle through your different pre-set lighting levels. A small LED on the switch lets you know which setting you’re on.
This feature can be perfect for your home theater. At the touch of a button you can go from full brightness to 15% dimmed for the movie. Then, when the movie is over, touch it again to bring the lights up just slightly so you can see but not damage your eyes!
Add a remote control
Other dimmer switches let you control the lights without ever getting off the couch, like the Lutron Caseta Wireless Dimmer with Pico Remote Control.
Need help selecting or installing a dimmer switch?
Let a professional, trained George Brazil electrician help. We serve the entire Phoenix area and can help you find the perfect dimmer switch and install it for you.