• Compatible with conventional gas, oil, electric or heat pump systems up to 3H/2C.
• Unsurpassed ease-of-wiring with only three wires to connect between devices.
• True communicating system using standard thermostat wire.
• Networked zoning enables these features: Time synchronization.
• Shared-filter indication. Outdoor temperature display in all zones with only one C7089B Outdoor Temperature Sensor connected.
• Vacation Hold in all zones.
• Selectable high and low equipment protection settings.
• Adjustable stage timing.
• Adjustable purge timing and damper positions.
• Expandable up to nine zones with W8703 Damper Interface Module.
• Single network can use up to nine T8635L Thermostats and two W8703 Damper Interface Modules to control nine zones.
• Telephone access when used with optional W8735B Telephone Access Modules.
• Uses Zone of Greatest Demand Intelligence.
• Allows use of EnviraCom furnace board or traditional furnace boards.

Optional use of two transformers for power when many dampers are needed

Information on the C7835A1009 Communicating Discharge Air Sensor:
Duct-mounted temperature probe used to provide capacity control of heating and cooling equipment. Used with Honeywell Network Zoning System and single unit zone applications.

• When mounted in supply air duct, DATS senses delivered air temperature and cuts off heating or cooling when delivered air temperature goes above or below normal operating limits.
• Compares discharge air temperature to room air temperature and when out-of- tolerance, issues alert to Panel
• Requires three wires.
• Uses standard 18-22 gauge thermostat wire.
  
  Information on the TH9421C1004 Thermostat
  The TH9421U touch screen universal programmable thermostat provides electronic control of 24 Vac heating and cooling systems of 750 mV heating systems in addition to humidification dehumidification and ventilation.
• Contains all features of standard VisionPRO, except arm chair programming.
• Thermostat connects with Equipment Interface Module to control temperature, humidification, dehumidification and ventilation from a single point in the home. Only 3 wires run from thermostat to equipment interface module (EIM), making retrofitting an old thermostat a snap!
• Can control whole house humidifier and automatically raises humidity levels throughout all rooms in the home, moisturizing air to prevent symptoms of dryness and to protect hardwood flooring and woodwork.
• Can control whole house dehumidifier, and automatically lowers humidity levels through al rooms in the home, utilizing air conditioning or a whole house dehumidifier to prevent dampness, stickiness or odors; symptoms often associated with air that is too moist.
• Can control whole house ventilation system, to bring fresh air into the living space.
  

• Zoning System Design Manual
• Zoning Made Effortless