Dear Mr. Electrician: How do I go about installing a ceiling fan using existing wiring to replace a light fixture in a house that was built in the 1970’s? The fan would be mounted onto an existing ceiling light fixture box on the first floor.
Answer: To install a ceiling fan using existing wiring it will most likely be necessary to remove the old ceiling light electrical box as it is not approved for ceiling fan support.
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If you want to convert a switched outlet to control a ceiling fan, read my blog post about that here.
Before working on the existing old wiring shut off the circuit breaker for this particular lighting circuit.
Start the removal process by disconnecting and separating the wires and identifying them with colored electrical tape or numbers. This will help when you put them back together.
My Ceiling Fan Wiring Diagrams blog post will be helpful for you with trying to decipher the existing wiring.
REMOVE OLD ELECTRICAL BOX FOR CEILING FAN
Loosen the screw for the wire clamp or unscrew the locknut on the cable connector. Remove the center screw(s) that holds the box to the support brace and carefully pull the box down while removing the wire from the box. Do not cut or damage the wires.
Removing the old ceiling box support bracket that is inside the ceiling can be difficult. I usually just use my 24″ bolt cutter’s to cut it in half. Then I swing the cut pieces forth and back to see if they loosen from the ceiling. Most of the time they are nailed in and the longer the nail, the more difficulty there is in removing the bracket.
I have some mini pry bars for just such an occasion. I can get a short pry bar up in the ceiling and reach over and get it behind the nailed-in bracket and give it a few tugs to get it loose enough for removal. Persistence is the key. If you get frustrated with the old box removal, take a short break and then get right back at it.
Once the old box and support has been removed you are free to install a new ceiling fan brace and fan rated box as per article 314.27(2)(C) in the National Electrical Code (NFPA 70). Also read article 422.18. The new ceiling fan braces are relatively easy to install. The ends of the brace are made in such a way that they will position the box at the correct height as they rest on top of the drywall ceiling.
Just line the brace up with the center of the hole and tighten it according to the manufacturers instructions. The fan brace will expand as you turn it and will bite into the joists. The brace should be straight and level as it goes from joist to joist and should be centered on the existing hole in the ceiling. If it’s not straight and level, loosen the brace and reposition it.
Confirm that the fan brace is solid by giving it a strong tug. Bring the wire into the fan box using a cable connector or clamp before attaching the box to the fan brace.
The fan box in the photo above attaches directly to the side of a joist. It can be installed during new construction or retrofitted many years after a home has been built.
Occasionally I have a ceiling fan installation that is not so typical and requires some thought and ingenuity to get a ceiling fan box installed. One of the most common out-of-the-ordinary installations is when double drywall is used on the ceiling. Other times I encounter resilient channel. This keeps the electrical box recessed back too far in the ceiling.
My simple fix is to buy a regular fan brace kit and also buy a separate 2-1/8″ deep fan box to use instead of the 1 1/2″ box that normally comes with the fan brace. It is possible to buy a fan brace with a deep box, however the legs on the brace are longer, therefore the deep box will not sit lower.
I have heard of other electricians cutting the legs a little to bring the box down. That works as long as the fan brace is able to lock into the ceiling joists.
INSTALL A CEILING FAN USING OLD WIRING
Ceiling fan manufacturers usually furnish installation instructions and many have simplified the process by the addition of a hook or hole to hold the fan motor up on the ceiling while you splice the wires together. Ceiling fan installations vary slightly by manufacturer and even from low end models to high end models within the same brand.
If installing a ceiling fan is new to you, I suggest that you read the instructions and also plan it out on a table or the floor how the ceiling fan needs to be assembled. Do not try to fully assemble the fan and mount it on the ceiling as a whole unit.
Start by grounding the new fan box with the existing bare or green ground wire and a green ground screw. Leave a grounding pigtail long enough to extend past the box a few inches. If needed, splice pigtails onto all of the existing wires to extend them a few inches beyond the ceiling fan box.
Next mount the bracket that came with the fan onto the ceiling fan electrical box using the screws and hardware that came with the fan brace and box kit. With the canopy and extension pipe already attached, hang the fan motor, from the hook or tab on the fan bracket. Make the electrical connections.
If installing a remote control, insert the receiver module into the bracket. This is usually a tight fit and the wires get in the way. Tuck the electrical wires inside of the fan box if possible. Tuck the wires in so that they don’t protrude from the canopy and then mount the canopy in place. It is okay if the wires are inside of the fan canopy. The fan motor should now hang freely with the canopy closed.
Many fan blades come with rubber grommets that must be inserted into the holes on each blade. For some fans the blades must be installed first before the light kit can be mounted. I use a screw holding type of screwdriver that holds the screws as I install each fan blade. Some fan blades are made to snap into place without screws.
The light kit is usually attached by plugging it into a modular plug inside of the bottom of the fan. Then the light canopy is attached using three small screws.
Here’s the link to all of my ceiling fan blog posts, some of which you will find helpful for your particular ceiling fan installation.