I am thinking about upgrading my Honeywell thermostat. Every thing I have seen describes / shows a single wire for each color. My current thermostat has two wires connected to each terminal (two green wires, two yellow wires, two black wires, and two red wires).
The new thermostat I want to install (a Nest) says to only insert one wire per connector. Is this a problem? Do I need to get my furnace rewired? Or, should I just keep the wires twisted together?