I want to make a few "whips". I need to upgrade my wiring. I have a circulator pump on a boiler to my aquastat, another wire from my aquastat to a motor, and another wire from one aquastat to another . The available cable at the store are 14/2 and 14/3 and each come in either solid or stranded wire. I'm assuming I would use the stranded. I'm not sure when you would use 14/2 over 14/3. Can someone explain the this. Also, when would you use solid over stranded? Thanks

I've done a lot of in-home electrical work, and it doing work in my home I discovered that all of my basement lights, my sump pump, and my two dehumidifiers are on a single 20A circuit that's shared with the upstairs bathroom! I need to remedy this situation without pulling three new lines from my existing breaker box. My service is 100A. I want to install a 40A or 50A sub-panel in the basement to supply the lights (15A), sump (20A), basement bathroom (20A), and dehumidifier (15A) and allow for any possible future expansion as well. This will leave the upstairs bathroom on it's own 20A circuit. So I know what I need to do from a basic level; all the basement wiring is easily accessible, so running the existing lighting and installing new circuits for the appliances to my planned panel location will be easy. What's hard: Running the #6 wire from the main panel to the basement. Do I need to use conduit, or can I use 6-3 Romex? How do I measure the correct amount of wire? I can buy a roll of 125', but if it's not enough, how do you splice it? My run has to go from the far wall of the garage, across the attic, then down the shaft next to the chimney (this is the most obvious location, but I am sure I can find another if the chimney shaft is a no-go zone). I plan to secure the new box on the unfinished side (outside) of the basement bathroom by installing a piece of 5/8" plywood to the exposed studs, then securing the new panel to that. Am I missing anything that could be a potential problem here?