I am replacing an OLD h/l/v with a BROAN 100HFL

I DO NOT have a 12/2 and a 12/3 coming from the 3 switches on the wall.

I DO have this, two 12/2 coming from the 3 switches AND another 12/2 that ran to a small light that came on with light in hlv

The heater has one red and one white. The light/fan has a white/blue/black

I got the heater to work connecting the black to red and white to white..... but do not have the 3rd RED wire coming from wall switches.

I know this is out of code, but CAN NOT run new wiring.

Can someone help me out here?? I know it can be done easily, just having trouble as I am just not an electrician!

  • Some pictures might help. I'm confused, you have 3 switches (assuming one for light, one for fan, one for heat), but only 2 12/2 cables? – Tester101 Feb 9 '12 at 13:55
  • Help me with this, Please...I DO have this, two 12/2 coming from the 3 switches AND another 12/2 that ran to a small light that came on with light in hlv...What does the 3rd 12/2NM do? – lqlarry Feb 10 '12 at 2:44

I'm not sure why you have 3 switches, and only 2 12/2 cables. But I'll give it a stab anyway.

The fan unit should have

  • 1 Red wire.
  • 1 Black wire.
  • 1 Blue wire.
  • 2 White wires.
  • 1-3 Green or Bare wires.

The red wire in the unit should control the heat, so you'll hook the black from one switch to the red wire of the unit, and the white wire from the same cable to the white wire for the heater.

Next because you only have one more 12/2 cable from the switch bank, your light and fan will have to be controlled by the same switch. So you'll connect the black wire from the switch to both the black and blue wires on the unit, then the white wire from the same cable to the white wire for the fan/light.

If you want the other light to come on with the light/fan, hook the black wire to the light in with the black/blue wires on the unit, and the white wire to the light in with the white wire at the unit.

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These instructions are for a typical installation, your situation may vary. Wire colors may vary from unit to unit, consult the manufacturers documentation for proper wiring diagram. Contact an Electrician before proceeding.

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This is an old question that was not ever properly answered? I understand that the installation instructions call for a 12/2 and a 12/3 cable because that's all that's needed. However, the OP has 3 - 12/2 cables because another light is switched with the unit light. 2 of the cables in the unit box go to a three gang switch box. The other cable runs to another light that still should be switched with the unit light. Thus there is another 12/2 that must run from the other light to the three gang switch box.

Unfortunately, I don't have convenient means to make nifty drawings like Tester101. I'll stick with a verbal description, hopefully someone can help me out with an illustration.

  1. Turn off all breakers supplying power to the switches, light, H/L/V.

  2. Connect all green and bare wires (grounding) together.

  3. Connect the cable from the heat switch to the heater, black cable wire to red heater wire, white cable wire to white heater wire. Temporarily restore power only for the heater circuit, turn on the heater switch, and ensure the heater works. The heater should be on it's own circuit, not shared with fan and lights. If this test fails, turn off power and disconnect the currently connected cable and connect the other cable from the switch box. Re-test. Turn off the power again to be safe.

  4. The remaining cable from the 3-gang switch box controls the fan. Connect white cable wire to unit common white wire, black cable wire to black fan wire.

  5. The cable from the other light controls the unit light. Connect black cable wire to blue unit light wire. Connect white cable wire to the same unit common white wire as the fan.

  6. Restore power and ensure everything works as it should.

This installation completely meets Code, even if it differs from the installation instructions.

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  • FWIW I often use CoSketch to make garish but functional illustrations. It's a collaborative whiteboarding app, but it works well enough. I'd be happy to learn of better tools; sounds like a good Meta post. – Jeremy W. Sherman Sep 21 '12 at 23:03
  • Sorry if the edit bump threw you off. I was cleaning up questions that were using the bath tag before creating a bathtub synonym. – BMitch Sep 21 '12 at 23:11

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