How to wire a bathroom extractor fan

Updated February 21, 2017

Bathroom extractor fans help control unwanted odours and excess humidity. Excess humidity can cause mould and other respiratory health issues. These fans are designed to change the air inside a bathroom at a specific rate. The air inside a bathroom should change approximately 8 times per hour. This is why these fans are sold based on how much air they can move within a given time.

Shut off the power to the bathroom circuit that will feed the extractor fan.

Open the fixture electrical box that will provide power to the fan. For a simple installation, locate the black and white feed wires inside the electrical box.

Remove the existing plastic twist caps on the existing splices. Do not separate the wires. At the fan unit, locate the black and white fan wires. Strip 1/2 of an inch of insulation off of these two wires if they are not factory stripped.

Connect the white wire of the fan to the white wire splice in the electrical box. Place a plastic twist cap on this splice. Connect the black wire of the fan unit to the black splice which contains the switch wire. The switch wire could be black or white depending on what colour wire runs from the switch. If it is white, it should have been marked to indicate that in the electrical box. Place a plastic twist cap on this splice.

Close the electrical box, and turn the power back on. Test the fan for proper operation. The installation described is a simple installation. More complicated installations require knowledge of the manufacturer's installation instructions.

Things You'll Need

  • Screwdriver
  • Wire strippers
  • Wire cutters
  • Plastic twist caps
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About the Author

William Kinsey lives in Concord, N.C. He started writing articles in March 2009, which have appeared on and He currently holds a Bachelor of Science in electrical engineering from the University of North Carolina at Charlotte and a Master of Business Administration from the University of Phoenix. He also has several years experience as an outside plant engineer and planner with AT&T. He also currently owns and operates Sophisticated Curves, an online fashion mall that caters to the needs of plus size women.