I am in the process of replacing a bath fan/heat lamp combo in a master bath. My son disconnected the wiring from the old unit and removed it without labeling the wires. Now I have questions regarding the correct way to reinstall the unit and wiring.

The old unit had one 12-2 with ground for power input to the box and two 12-2 wires with ground going from the box to two switches (one for the 2 lamps, one for fan). I plan on using this same wiring configuration for the new unit.

Both switches have the black wire on the top screw and the white wire on the bottom screw. The grounds are connected to the green screw and grounded correctly in the box.

According to the installation manual, the units electrical wires are as follows (2 lamp model):

Black = fan control
White = Neutral
Light Blue = heat bulb control
Dark Blue = heat bulb control
Green = ground


I'm not familiar with how to wire since the power is usually from the switch to the unit, not this way. I have the instruction manual so I know how I would hook it up if the power was direct from the switches, I just don't know about how to do it with the power the way it is now.

I believe I should hook up the black wire from the supply feed to the white wires for the two switches, then use the black wires from the switches as switched power to the lamp and fan control on the unit. Is this correct?
Thanks

 

That sounds like you may need a special switch and a 3-conductor cable for the heat.

 

The unit I replaced just had a switch to control both lamps together - I hooked this one up the way I mentioned in the post earlier and everything is working fine.

 

The way you connected it is fine. Instead of using a 3 wire, the person who wired your house used 2 pieces of 2 wire. Either way.will work.