For decades, changing out a thermostat for a retrofit hydronic heating system was a simple task for a service technician. From Bangor, Maine, to Breckenridge, Colorado, the mere two, 18-gauge thermostat wires running through a home was not a concern (short of the random nail or mouse taking one of the two out).
However, the explosion of the Internet of Things (IoT) and the smart home industry changed everything for our trade. Demand for a third, common wire for a constant 24 volts for Wi-Fi connectivity drove some technicians mad across the country. Soon wireless controls, two-wire thermostats with super capacitors and other technologies came and went.