Growing up, I learned several DIY projects from my dad by observing him as he worked on home improvement projects.
He was handy with his tools.
He went around the home, fixing structural and decor flaws at home. He couldn’t even help it when he was out visiting friends. His eye for perfection always observed something that needed fixing, especially HVAC equipment, and we all loved him for this. I watched him wiring an electric furnace thermostat carefully and learned how to do it. A while back, I saved a friend some bucks that he would have otherwise paid for his furnace thermostat wiring. The process is relatively easy. Begin by turning off the air handler or electrical circuit to the furnace. Note down the wire colors and the terminals where each wire goes through. Better yet, take snapshots of everything you do while removing the old thermostat from your HVAC system. My dad used the old-school method of labeling all the wires on the thermostat by marking each terminal and their corresponding wires. These notes or pictures will come in handy later while wiring your new thermostat. After that, disconnect the old thermostat and remove it. Put the new thermostat in place and begin re-wiring it to the terminal. Use your labeling notes or pictures to complete this process. Connect the wires one by one until you’ve reinstalled all of them and your new thermostat is in place. At this point, the work is done, but to confirm that it’s functioning properly, turn on the electrical circuit and adjust the new thermostat to start the cooling or heating process. The thermostat should work just fine if the wires are attached accurately. If not, you might want to examine each terminal and the wire attached to it.