17+ Replacing Old Thermostat Only 2 Wires. I'm replacing an old thermostat from the early 90's with a new wifi thermostat. Check out my tutorial because you'll get a ton of useful tips.
Want to learn how to replace an old thermostat? A thermostat is a tool that regulates heating and cooling, whether it be in your home or in your car. Disconnect the wires from the old thermostat.
The name has become ubiquitous with any of the simple dial thermostats, even if they were manufactured by an array of different companies.
My old thermostat uses only 2 wires, attached to the r and w terminals. There is no instructions to say what to connect when you have a 3 core cable of live, neutral and earth. Need help updating a really old thermostat king859. The thermostat instructions call for a red power wire, a yellow, green and white wire.