Honeywell/Resideo TrueZONE systems divide a single forced-air HVAC system into independent comfort areas using motorized dampers, dedicated thermostats, and a central control panel.

 

Core Applications & Panel Selection

Choose the panel based on equipment staging, fuel source, and total zone count:

 

Panel	Max Zones	Compatible Equipment	Best Use Case
HZ221	2 Zones	Standard Heat Pump (1H/1C) or Conventional (1H/1C)	Basic single-stage heat pumps or entry-level 2-zone homes.
HZ311	3 Zones	Conventional Single-Stage (1H/1C only)	Simple multi-zone split systems or gas furnace/AC combos.
HZ322	3 Zones	Up to 2H/2C Conventional or 2H/1C Heat Pump	Standard multi-stage gas/electric or heat pump equipment.
HZ432	4 Zones (expandable to 32 via TAZ-4)	Up to 3H/2C Conventional, 4H/2C Heat Pump, or Dual Fuel (Fossil Fuel kit built-in)	Advanced multi-stage systems, dual-fuel heat pumps, or commercial/large residential zoning.

System Architecture: Required Components

Every Honeywell TrueZONE install requires five essential pieces:

 

• TrueZONE Control Panel: (HZ311, HZ322, or HZ432) Acts as the brain, processing calls from thermostats and dispatching commands to the HVAC board and dampers.

 

• Dedicated 24VAC Transformer: (AT140A / AT175A) Zone panels must have an independent, dedicated 40VA (up to 3–4 standard dampers) or 75VA (larger commercial/retrofit jobs) transformer. Never pull power from the air handler's internal transformer.

 

• Discharge Air Temperature Sensor (DATS): (C7735A1000) Mounts in the supply plenum downstream of the evaporator coil/heat exchanger. Essential for high-limit and freeze protection (cycles equipment off if supply air drops below ~40°F in cool mode or exceeds ~160°F in heat mode).

 

• Motorized Zone Dampers:

   

  • ARD / ZD series: Standard 24V power-close / spring-open dampers (use M1 and M6 terminals).

  • RRD series: Round retrofit dampers that slide directly into existing round branch runs.

  • Power Open / Power Close: 3-wire dampers utilizing M1 (Common), M4 (Open), and M6 (Close).

 

• Static Pressure Relief / Bypass Strategy:

   

  • Barometric or Modulating Damper (CPRD): Relieves excess static pressure when only one small zone is calling.

  • Alternative: Duct sizing allowing continuous bleed through dampers, or dedicated oversized dump zones.

 

 

• Thermostats / Wireless Interface: Standard 24V wired thermostats, or a RedLINK Wireless Adapter (THM4000R1000) paired with RedLINK FocusPRO/VisionPRO thermostats for hard-to-wire locations.

General Wiring Diagram & Terminal Breakdown

                    +---------------------------------------+
                    |          24VAC Dedicated              |
                    |          Transformer (40VA)           |
                    +-------------------+-------------------+
                                        | (24VAC & COM)
                                        v
+------------------+         +---------------------+         +---------------------+
| Zone Thermostats |         |  Honeywell TrueZONE |         |    HVAC Equipment   |
| (Zone 1, 2, 3)   | ------> |    Panel (HZ322/432)| ------> |    Control Board    |
+------------------+ (R,C,W,Y,G)   +----+-------+---+ (R,C,W1,W2,Y1,Y2,G,O/B,etc.)
                                        |       |
                 +----------------------+       +----------------------+
                 | (M1, M4, M6)                                        | (DATS Terminals)
                 v                                                     v
      +--------------------+                                +--------------------+
      | Motorized Dampers  |                                | DATS Supply Sensor |
      | (ARD / ZD / RRD)   |                                |     (C7735A)       |
      +--------------------+                                +--------------------+

Key Terminal Map

• POWER: 24VAC (Hot) and COM (Common) from dedicated transformer.

• EQUIPMENT:

   

  • R / RC / RH: Equipment 24V reference.

  • C: Equipment common.

  • W1/E, W2/AUX: Staged heat.

  • Y1, Y2: Staged cooling / compressor.

  • G: Fan relay.

  • O/B: Reversing valve (configured via panel digital menu for B or O).

• ZONES (1 through 4):

   

  • R, C: 24V thermostat power.

  • W, Y, G: Conventional heat, cool, and fan calls.

  • O/B: Direct heat pump inputs if applicable.

• DAMPER OUTPUTS (Per Zone):

   

  • M1: 24V Common / Power.

  • M4: Power Open (for 3-wire dampers).

  • M6: Power Close (standard 2-wire uses M1 & M6).

• SENSORS / EXPANSION:

   

  • DATS: 2-wire connection to discharge air sensor (polarity does not matter).

  • OT: Outdoor air temperature sensor (used on HZ432 for dual fuel balance points).

 

Notes:

 

For air to air heat pump applications: Either use heat pump thermostats for each zone or use the HZ432 panel and use the built in dual fuel change over. The HZ432 option is much easier.

 

To see the redlink panels online, you will need to add the redlink gateway (THM6000R7001/U) as well.