Properly Performed spring/fall maintenance 3 systems. Replaced all filters checked blower wheels for built up dirt/dust, cleaned flame sensors, cleared inducer ports, tested hot surface igniters, took delta Ts, cleared drain lines, tested safety switches, tested all electrical components, tightened all electrical connections, took running volts/amps, monitored systems operations. 36 degrees outside temperature, did not turn AC on. The main floor system water safety switches were not connected correctly. I fixed issue and tested wet safety switch. Wet safety switch is working properly.