If you’ve installed more than a few thermostats, you’re likely to have come across many that have four wires. Typical 4 wire thermostat (t-stat) wiring examples follow. Some have the common (C) wire, while others do not. Both examples of how to wire a Honeywell thermostat with 4 wires we describe next. How to Wire … Continue reading How to Wire a Honeywell Thermostat with 4 Wires