Tag: TH4210U2002/U

Honeywell Home T4 Pro Thermostat Wiring Diagrams WIRING DIAGRAMS Stage Heat Only: Gas or Oil Furnace COMMON OPTIONAL. USED FOR INDEPENDENT FAN CONTROL ONLY. MOST HEAT-ONLY, GAS OR OIL-FORCED AIR SYSTEMS DO NOT USE A FAN WIRE. Stage Cool Only   1H/1C: Gas Furnace COMMON OPTIONAL. Transformer System, 1H/1C: Oil Furnace   Transformer System, Hot…