HVAC Zoning - Zone 1 Priority Using ECO Mode on SmartZone

In many HVAC zoning applications, it’s beneficial to prioritize one thermostat — typically Zone 1 — so that its heating or cooling demand takes precedence over all others. This ensures the system responds first and foremost to the most important area of the building, such as a main living space, master suite, or temperature-critical zone.

The SmartZone makes this easy using its built-in ECO Mode feature. When ECO Mode is active, the panel ignores thermostat calls from all other zones and operates solely based on Zone 1.

By wiring the Zone 1 thermostat’s “G” call signal to the ECO terminal, the panel will automatically enter ECO Mode whenever Zone 1 is calling. When the call ends, ECO Mode is released and normal multi-zone operation resumes.

How ECO Mode Works

• ECO Mode Active: Only Zone 1 thermostat calls (heat, cool, or fan) are honored. All other zone calls are ignored until ECO Mode is released. NOTE: Zones 2 and up dampers will still open and close with calls from their respective thermostats as usual.

• ECO Mode Inactive: The system operates normally, responding to calls from all zones according to priority and demand.

This feature helps reduce short cycling between zones, saves energy, and maintains stable comfort in the most-used area of the home or building.

Prioritizing in Heat Only or Cool Only Modes

In some applications, it may be desirable to prioritize Zone 1 only during heating or only during cooling operation. This selective approach allows the system to favor one zone under certain conditions without restricting comfort for the rest of the building year-round.

1. Heat-Only Priority

When configured for heat-only priority, ECO Mode is activated only during a heating call from Zone 1.
This setup is ideal for applications where heating needs differ greatly between zones — for example:

• Two-story homes: The main level (Zone 1) tends to lose heat faster than the upper floor. Prioritizing Zone 1 during heating keeps living areas more comfortable and prevents overheating upstairs.

• Commercial offices: A front lobby or entrance area may require quicker heating recovery when doors are frequently opened to cold outdoor air. Giving Zone 1 heat priority ensures this space warms up first.

• Single furnace with multiple small zones: Helps avoid rapid cycling and ensures the furnace completes a full, efficient heating run focused on the primary zone.

In this case, ECO Mode can be tied only to the W (heat call) output from the Zone 1 thermostat.
(Refer to the “Heat Priority Wiring” diagram for details.)

2. Cool-Only Priority

For cool-only priority, ECO Mode is enabled only during a cooling call from Zone 1.
This configuration is useful when one area tends to overheat faster or carries the main cooling load — such as:

• Homes with large west-facing rooms: These spaces experience significant solar gain and may need cooling sooner and more often than interior zones.

• Light commercial buildings: A server room or glass-walled conference area may require priority cooling to protect equipment or maintain comfort during peak hours.

• Multi-zone systems with limited cooling capacity: Ensures the system focuses on critical cooling areas first, improving overall comfort and system efficiency.

In this setup, ECO Mode is wired to the Y (cool call) output of the Zone 1 thermostat.
(Refer to the “Cool Priority Wiring” diagram for details.)

When to Use Zone 1 Priority

Use Zone 1 priority when:

• One space represents the primary comfort zone for occupants.

• You want to minimize system short cycling caused by competing zone calls.

• The HVAC equipment has limited capacity compared to the number of zones.

• Efficiency and comfort are higher priorities than maintaining all zones simultaneously.

When not needed, the ECO Mode input can simply remain open (unconnected), and the SmartZone will resume standard zoning logic, responding to all thermostats equally.

SmartZone-3X 3.0

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SmartZone-4X 3.0

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Ecojay SmartZone vs. Honeywell TrueZone: Which Zone Controller Is Better?

When it comes to residential HVAC zoning, the control panel is the brain of the system. It determines how effectively your home’s heating and cooling are distributed across different zones. Two of the most talked‑about options on the market are the Ecojay SmartZone series and the Honeywell TrueZone series. But which one is the better choice for homeowners and contractors in 2025?

Let’s break down both options, their pros and cons, and see which zone controller comes out on top.

Why Choosing the Right Zone Panel Matters

A zone control panel manages thermostats, dampers, and HVAC equipment so each zone in a home can be independently heated or cooled. The right panel makes installation simple, reduces troubleshooting headaches, and ensures maximum comfort and energy savings. The wrong choice can mean callbacks, frustration, and unhappy homeowners.

Ecojay SmartZone Overview

The Ecojay SmartZone 3.0 series (including the SmartZone‑4X and SmartZone‑3X) is a newer generation of zone panels designed with contractors and DIY‑savvy homeowners in mind.

Features and Benefits

• Universal compatibility with almost any 24VAC thermostat and damper system

• Supports conventional, heat pump, dual‑fuel, and multi‑stage systems

• Built‑in supply air sensor for equipment staging (up to 3H/2C)

• LED indicators for easy wiring and troubleshooting

• Simple installation and clear labeling

• Strong 5‑year warranty and U.S.‑based support

Pros

• Works with virtually any system configuration

• Faster installs thanks to intuitive wiring

• Reliable long‑term performance

• Excellent customer support and documentation

• Expandable (up to 20 zones) for future-proof install

Cons

• Ecojay does not sell or offer thermostats (This could be seen as a PRO because it means you are free to choose any thermostat you want)

Honeywell TrueZone Overview

The Honeywell TrueZone series (HZ322, HZ432, HZ311, etc.) has been around for years and is one of the most common zoning platforms found in homes today.

Features and Benefits

• Designed for 2‑, 3‑, and 4‑zone setups

• Familiar brand with widespread availability

• Works with most Honeywell thermostats

Pros

• Well‑known name in the HVAC industry

• Often used by contractors familiar with Honeywell systems

• Good availability through wholesalers

Cons

• Reported reliability issues, with frequent replacements needed after only a few years

• Must use Honeywell thermostats

• More complicated wiring and setup compared to SmartZone

• Limited staging and fresh‑air integration features

• Support is limited to “authorized dealers”

Which One Should You Choose?

If you want ease of installation, maximum compatibility, and long‑term reliability, the Ecojay SmartZone series is the clear winner. The SmartZone‑4X is ideal for larger homes (4 zones - Up to 20 with expandability), while the SmartZone‑3X is the best value for mid‑sized setups.

Honeywell TrueZone panels still have their place, especially for contractors who work mainly with Honeywell thermostats. However, reliability concerns and fewer advanced features make them less attractive for new installs in 2025.

Where to Buy Zone Control Panels

At ZoningSupply.com, you’ll find the full range of Ecojay SmartZone control boards, dampers, and accessories, along with replacement parts for Honeywell and Arzel systems. Whether you’re upgrading an existing setup or starting fresh, we have the products and support to make your project a success.

✅ Final Verdict

• Best Overall: Ecojay SmartZone‑4X (ZS4X‑3.0)

• Best Value: Ecojay SmartZone‑3X (ZS3X‑3.0)

• Still Available: Honeywell TrueZone (HZ432, HZ322) for legacy installs

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SmartZone-4X 3.0

Sale Price: $269.99 Original Price: $299.00

SmartZone-3X 3.0

$199.99

When it comes to performance, reliability, and support, Ecojay SmartZone is the smarter choice for HVAC zoning in 2025.

How to Operate an HVAC Zoning System Efficiently

Managing your home's HVAC system efficiently ensures comfort, energy savings, and longevity for your equipment. With a 4-zone SmartZone control system, Vine connected Wi-Fi thermostats, and EcoJay’s Outdoor Temperature Controller with free-cooling features (economizer), you have the tools to achieve optimal performance. Here are some tips to get the most out of your setup:

1. Set Smart Thermostat Schedules

Using the scheduling feature on your Vine Wi-Fi thermostats is one of the easiest ways to save energy:

• Create zone-specific schedules based on occupancy. For instance, prioritize heating or cooling in bedrooms during the night and in common areas during the day.

• Set back temperatures when zones are unoccupied. For example, raise the cooling setpoint by 4–6°F or lower the heating setpoint by 8–10°F.

2. Take Advantage of the Free-Cooling Feature

The free-cooling feature, also known as an economizer, can reduce energy usage by leveraging outdoor air for cooling when the conditions are favorable. EcoJay’s Outdoor Temperature Controller makes this easy:

• Understand the conditions for free-cooling: Free-cooling is effective when outdoor air is cooler than your indoor setpoint and has low humidity.

• Configure your economizer settings:

  • Set the temperature threshold on the Outdoor Temperature Controller to activate free-cooling (e.g., when outdoor temperatures are below 60°F).

  • Adjust the dampers to let in fresh, cool outdoor air while minimizing mechanical cooling.

• Use during transitional seasons: Spring and fall are ideal for economizer use, as outdoor temperatures are often moderate.

• Monitor system operation: Ensure the economizer dampers and controller are functioning correctly to avoid overcooling or bringing in excessive humidity.

3. Balance Zones Appropriately

• Ensure proper damper operation: Verify that the dampers for each zone respond correctly to thermostat commands. Stuck or malfunctioning dampers can lead to inefficiency and discomfort.

• Avoid extreme setpoints: Large temperature differences between zones can strain your HVAC system. Keep setpoints within 5°F to 10°F of each other for smoother operation.

• Minimize unused zones: If a zone is rarely used, set its thermostat to a minimal setting to conserve energy while ensuring the zone doesn’t fall too far out of the desired range.

4. Optimize Ventilation and Airflow

• Keep vents clear: Ensure furniture or curtains do not block air supply and return vents.

• Regularly clean filters: Dirty filters restrict airflow, making your system work harder. Replace or clean filters every 1–3 months, depending on usage.

• Inspect the ductwork: Leaks in ducts can lead to significant energy loss. Seal any gaps with professional-grade duct tape or mastic sealant.

5. Use Thermostat Features Wisely

Vine thermostats have smart features to enhance efficiency:

• Enable geofencing: This adjusts settings automatically based on whether you’re home or away.

• Monitor energy usage: Use the app to track heating and cooling patterns and make adjustments to schedules or setpoints.

• Utilize adaptive recovery: If your Vine thermostats support it, this feature gradually adjusts the temperature to ensure comfort by the time you’ve scheduled it, avoiding unnecessary overuse of the HVAC system.

6. Stay Ahead with Maintenance

• Inspect the economizer regularly: Dust, debris, or malfunctioning components can affect free-cooling performance. Clean and maintain the dampers, sensors, and outdoor air intake.

• Schedule professional checkups: A technician can ensure your entire system, including the SmartZone controller and economizer, is functioning efficiently.

Conclusion

Your SmartZone HVAC system, paired with Vine thermostats and EcoJay’s SmartZone PLUS Outdoor Temperature Controller, offers great potential for comfort and efficiency. By implementing smart schedules, leveraging free-cooling, balancing zones, and maintaining your system, you can enjoy a more energy-efficient and comfortable home.

Regular monitoring and adjustments ensure that your HVAC system meets your household's needs while keeping energy costs low.

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SmartZone-4X

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Outdoor Air Thermostat

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Why SmartZone is the best zone controller.

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• Screwless wiring (push-in) – No screwdriver required
• Color coded leds show inputs and outputs on every terminal – no voltmeter required
• EASY pushbutton & dip switch setup makes configuration a snap and confirmation of settings in just a glance – NO manual needed
• Temperature sensor included & supply temp displayed on the bright led display, visible even in the dark – NO flashlight needed
• MODES SHOWN ON DISPLAY tell you what the board is doing at all times in plain english – NO guessing what codes mean
• SmartZone can be used with any equipment – Heat Pump, Gas, Electric, radiant, geothermal, etc. as long as it is controlled by 24v.
• Single-stage & Multi-Stage equipment can be used (3 heat & 2 cooling stages)
• Heat pump equipment can be used with auxiliary & emergency heat – both electric and dual fuel -  flawlessly with SmartZone (requires heat pump thermostat connected to Zone 1)
• SmartZone can be paired with any thermostat from the most expensive WiFi stat to the cheapest mechanical thermostat.
• Any 24v damper (Spring or power) can be controlled by SmartZone
• Smartzone has exclusive advanced features:
  •     - Economy Mode allows setback of all zones with the     flip of a switch.  When in eco mode, the system will only     energize if zone 1 makes a call.  This feature is great for vacations or if some of the zones are rarely used.
  •     - Fresh air control allows control of an outside air damper and the system fan on a schedule to bring in fresh air in a prescribed amount.  If fresh air control is required, smartzone-4x has it covered with no additional controls required.  Save $
  • - Smartlink: expand to 20 zones by simply connecting multiple 4X boards together with the smartlink bus. Easiest & most cost effective system for more than 5 zones!
• Smart staging & limit protection – by using a sophisticated time and temperature algorithm perfected over decades of programming, smartzone stages up and down in the most effective and efficient manner possible.
• 2nd stage lockout – by setting this dip switch, smartzone will only allow 2nd stage if more than one zone is calling
• Stage from zone 1 thermostat – allows for a multi-stage thermostat to be connected to zone 1 and control zoning instead of SmartZone (not recommended in typical circumstances)