I have wired a bathroom fan into an exisiting bathroom with two 3-way switches controlling the light above the vanity. One of the existing 3-way switches is in the bedroom beside the bathroom. The power starts at that switch. Black and red 'traveller' wires run to the second 3-way switch inside the bathroom. I replaced the single outlet box in the bathroom with a double box so that I could wire a new 3-way switch for the fan. I ran a red and black wire from the two traveller screws on the existing 3-way switch for the light over to the two traveller screws on the fan switch. I then continued the power from the common screw up to the fan. The problem is that the 3-way switch in the bedroom still controls whether the fan comes on or off. My question is, can I use a single-pole switch for the fan and run the red and black wires from the 3-way switch over to the single switch. THis way, there will always be uninterrupted power to the fan switch. Power should only run through either the black or red wire and not both at the same time.
No, I had a very hard time following what you wrote, but i believe the answer is No. Why are you using a three way switch for the fan? Where are you going to get your neutral wire from? What I would do is find a circuit near the bathroom that has a insignificant load on it. Then run both the neutral and hot to the fan. Do not connect the hot to the fan, instead fish a two conductor wire w/ground to your new box. Use this as your switch leg. Then connect the hot coming into the fan to the white wire of the switchleg (mark with black tape), then connect the black coming from the switch to the hot wire of the fan and connect the white to the white of the fan. Please turn off the power when during this. And as a rule always connect ground then neutral, then Hot in that order, despite how i may have described it here. If you are still needing help i will check back later. Be careful!