New Circuit for Bath Heater/Vent, Part II
2007.06.24
Today I got started by getting up in the attic to drill a hole through the top of the wall so I could run the wires up. Oh how I hate working in this attic…
My house has a hip roof (meaning it slopes in on all four sides, sort of like an elongated pyramid) with a shallow pitch. Even right in the middle, on my knees, I can reach up and touch the ridge beam, so there’s nowhere to stand up, and hardly anywhere to even sit up. The bath vent unit is over towards the back corner, so I’ll likely have to lay down across the ceiling joists to work on it.
Preparing to run wires up to attic
Next to the bathroom door are two switches. One turns on the lights, and the other turns on the vent fan (and associated light). Up in the attic I could see where these wires came up out of the wall.
I measured down below where I’d pulled the wires through at the bottom of the wall, and then went up in the attic to measure up there to figure out where to drill a new hole. I pulled back the insulation and… hey look at that, someone already drilled one for me! That’s the first thing that’s gone unexpectedly right for me on this project. Or any project, for that matter.
Planning the project after you've already started
Back to the two switches: the challenge here was that I needed at least three things to be operated independently; the main lights, the vent fan, and the heater.
I was planning on installing a new box with three rocker switches, to operate the vent fan, heater, and light in that unit. I had purchased the three-rocker switch way back when I bought the heater/vent unit itself.
As I looked at the instructions and wiring diagram for the switch, I realized I would need three hot leads, plus neutral and ground. So the 12–2 wire I had wouldn’t cover it. I would need some 12–3 wire, and then still need an additional hot wire. Well, if I wired the vent fan and light together on one switch (as they were now), then I’d just need the 12–3 wire.
Another issue that dawned on me was that I was going to disconnect the second existing switch in lieu of this new rocker switch setup further along the wall. Seems like it would be weird to have a switch on the wall that did nothing. Hm, I guess I could rewire it as an outlet.
In retrospect, what I should have done was figured out a way to install a two-rocker switch in place of the single regular switch, next to the other regular switch, with a new cover plate that would accommodate it. But I had already pulled the wires up to the attic further along the wall and decided to install a new single-gang box there. Oh well.
At any rate, I took off the cover plate to have a look at the two switches. It seems that when they sprayed on the “orange peel” drywall texture and paint, they sprayed right into the open electrical box. So the whole inside of the box, all the wires and wire nuts, and the normally-hidden parts of the switches themselves are all a nice shade of beige. Did you know that once upon a time there was craftsmanship and care in American home construction?
So I made a trip to Lowes to get some 12–3 wire, a new two-rocker switch, a new outlet and, why not, a new single switch for the lights.
New switch box in bathroom
I drilled and cut a hole for the new box. Of course the first hole I drilled went right into a stud. (And I cleverly scored the wall around the box with a utility knife where I thought it would go.) Why do I not test these things out discreetly beforehand? Have to patch and repaint that at some point. I fished up the 12–2 wire from the basement, and then ran the 12–3 wire down from the attic, and got the new box installed.
Electrical 201
Wiring up the two-rocker switch was a little more complicated than the outlet I put in the garage ceiling. There’s really just one extra wire, but I checked the diagrams and thought about it a while before diving in (impressive, I know).
The ground wire from below (incoming from the panel) and above (outgoing to the attic) get pigtailed with a short ground wire connecting to the switch. The neutral wire bypasses the switch altogether. Then the incoming hot wire connects to the switch (on the left side, in this case).
The 12–3 wire has a fourth wire (I know, why don’t they call it 12–4, and the regular stuff 12–3) which can be used as a second hot line. This wire is typically red (while the first hot wire is black). These get connected to the two hot terminals on the right side of the switch. Internally, the incoming power from the left side is split through the two rocker switches and out on the right side.
Well, it took most of the weekend to get this far. I’ll have to continue next weekend.
Bath Heat/Vent