Honeywell’s Thermostat Wire Saver User Guide

Honeywell’s Thermostat Wire Saver The wire saver (AKA: THP9045 Wiring Module) is designed to be used with applicable thermostats in which a 24V common wire is required but the homeowner does not have a common wire connected to their current thermostat. The required wire 24V common wire powers the thermostat. Honeywell’s wire saver acts like a splitter and replaces the need for a 24V common wire to be run from the HVAC system to the thermostat.
download here Honeywell’s Thermostat Wire Saver User Guide