How do I know if I need a 5 wire or 7 wire spool of wire for my Thermostat to my units? I am setting up my central heat and air. Everything is run but the t-stat wire. My t-stat manual just shows how to hook it up. ANy info would be appreciated.
Check the manual for the device on the other end, you might get closer, usually the t-stat will only tell you which wire goes to which terminal. You've left out a bunch of details...like the type of system do you have, is your AC a single or dual stage unit? Do you have a boiler?
when it comes to breakfast, the chicken is dedicated, the pig is committed.
You are better off to run a 6- 8 conductor dependant upon how many stages of heat and cooling you have. Maybe even use them for a humidifier if you need. Even if you have too many wires, you can just leave them disconnected behind the tstat and use them in the future if one of your wires has a break.