Hot Topics: Replacing Ceiling Fans When a Dimmer Switch Is in the Way

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When you’re planning to install new ceiling fans, you might run into some wiring problems. Though the problems might be from past owners or poor wiring, you know the Forum members can help you find the solutions.

Original Post: ceiling fan w/cfl and dimmer switch

junestan Member

I have two ceiling fans with no lights in my living room. There are also two ceiling mounted lights in the room. All four are operated by one dimmer switch. I'd like to replace the existing fans with fans that have lights. Almost all the fans available come w/cfl lamps. So my questions:

If the cfl is "dimmable" will it work on my existing dimmer switch?

- Can I replace cfls with incandescents?
- If I do, will they work on my dimmer?
- If I get one that says it's not dimmable, will it work on my dimmer but just come on full power?


Highlights From the Thread:

ray2047 Group Moderator

Fans can not be on dimmer switches. It is bad for the motor. They can be on speed controls but if they have pull chain switches the switches must be left on high when speed controls are used.

CFLs lights must be intended for a use on a dimmer circuit. Just any CFL will not dim. Nor can you use any dimmer. The dimer must be made for CFLs.

You will probably have to add cable to add lights or use remote controls.

junestan Member

One of the previous owners of my house did some pretty hokey work on it. There used to be 4 ceiling lights, all on the same dimmer switch. They replaced two of the lights w/fans and all 4 work off of the same switch. The dimmer dims the lights and slows the fans. I virtually never use the fans so just turned them off w/the chain switch. I mostly want to replace them because they're cheap and ugly. I haven't looked at the wiring yet but assume it's 1 white & 1 black. The house is 53 yrs old so the original wiring is ungrounded.

I did find a fan I like w/dimmable incandescent lights. It sounds like I couldn't wire that into just 2 wires? Adding wires isn't doable as the fans are mounted on beams below a cathedral ceiling w/no access.

ray2047 Group Moderator

There are fans with remote controls that require only two wires but they cannot be used on a circuit controlled by a dimer. You might be able to add universal remote control dimers to the ceiling lights and bypass the existing dimmer all together.

junestan Member

The box that the dimmer is in is large. Maybe there was originally a rheostat in there and didn't the old ones used to need lots of room? The box measures 5" wide x 7.5" tall. The dimmer is mounted vertically in the middle of the top part which is 5" x 5.5". It has 2 black wires coming from it. There are 4 sets of wires in the bottom compartment. Couldn't I leave the lights wired to the dimmer switch and install another regular switch next to the dimmer for the fans? I assume the wall switch would send power to the fans and I'd control the fans and lights w/the chains that hang from the fans. The fan's wiring diagram shows the pull-chain wiring as using just two wires (plus a ground) from the house.
Thanks for all the help!

Nashkat1 Member

If you only have two wires from the wall to the ceiling, you can't control a ceiling fan, the light on the ceiling fan, and some regular ceiling lights without using remote controls. Your best option might be to install home automation controls such as those made by X10 and Insteon.

You can also install a combination fan/light controller for that fixture and the automation remotes for the regular lights.

That sounds like a custom box that might have housed remote relays at one time. Standard rheostat home lighting controls have been made to fit in single-gang or 2-gang switch boxes since well before your house was built.

junestan Member

Should have done this first thing. Here are the wires. I have more than I thought.

sketch of the wiring

There are 4 groups of wires coming into the box:

- The dimmer wires
- What I think is from the fans and lights (it has been worked on; is taped up w/black elec tape)
- Two from the house (?). They're both Romex-type (looks like Romex but has a silvery outer covering instead of plastic).

Did the sketch help solve the issue? See the rest of the conversation at: //