TL:DR – You can get it here 🥳

Its been way too long in the making. But its finally done (well…maybe a few small tweaks left!)

One of the biggest challenges when integrating HVAC systems into Home Assistant is controlling 24VAC devices like duct dampers and zone valves.

Most smart home relay boards are designed for 5V, 12V, or 24V DC, but HVAC systems use 24V AC control circuits.

This makes it surprisingly difficult to build a reliable ESPHome HVAC zone controller.

After running into this problem while automating a ducted air-conditioning system, I built a dedicated ESPHome 7-zone HVAC controller designed specifically for 24VAC systems.

Here’s the controller board.

Why HVAC Automation Is Difficult

Most ducted HVAC systems use 24VAC control wiring.

Typical zone dampers work like this:

24VAC OPEN
24VAC CLOSE

Applying power to one line opens the damper, while applying power to the other closes it.

The problem is that most smart relay boards cannot safely switch 24VAC loads, and they require complicated power conversions.

Typical DIY solutions look like this:

24VAC transformer
      ↓
rectifier
      ↓
buck converter
      ↓
ESP board
      ↓
relay board
      ↓
24VAC dampers

It works, but it’s messy and unreliable.

Introducing the ESPHome 7-Zone HVAC Controller

This controller board simplifies everything by running directly on 24VAC power while providing 7 relay-controlled zone outputs.

Core features include:

• ESP32 powered
• Native ESPHome firmware support
• 7 independent HVAC zones
• 24VAC powered
• Relay outputs for dampers or valves
• USB flashing port
• Terminal blocks for easy wiring

Because the controller runs ESPHome, it integrates seamlessly with Home Assistant.

Home Assistant HVAC Zone Automation

Once the board is connected to ESPHome, each zone appears as a switch in Home Assistant.

Example ESPHome configuration:

switch:
  - platform: gpio
    pin: GPIO23
    name: "HVAC Zone 1"  - platform: gpio
    pin: GPIO22
    name: "HVAC Zone 2"  - platform: gpio
    pin: GPIO21
    name: "HVAC Zone 3"

This allows you to create automations like:

open airflow to rooms currently occupied
close airflow to unused rooms
automatically balance airflow based on temperature
create independent climate zones

This turns a basic ducted HVAC system into a smart zoned HVAC system controlled by Home Assistant.

Ideal for Ducted HVAC Dampers

Most ducted air-conditioning systems divide airflow between rooms using motorized dampers.

Examples of zones might include:

Zone 1 – Living room
Zone 2 – Master bedroom
Zone 3 – Bedroom 2
Zone 4 – Bedroom 3
Zone 5 – Office
Zone 6 – Kitchen
Zone 7 – Theatre

Using ESPHome automation, you can dynamically manage airflow depending on demand.

Also Works for Irrigation Systems

Because the board switches 24VAC loads, it can also be used as an ESPHome irrigation controller.

Most irrigation solenoids work like this:

Common wire
Zone wire

Applying 24VAC opens the valve.

With seven relay outputs, the controller can manage multiple watering zones like:

lawn sprinklers
garden beds
drip irrigation
greenhouse watering

Why Not Use Commercial HVAC Zone Controllers?

Traditional HVAC zone controllers are often:

• expensive
• proprietary
• locked to specific thermostats
• difficult to integrate with Home Assistant

Many cost hundreds or even thousands of dollars.

This ESPHome controller takes a completely different approach:

• open platform
• DIY friendly
• Home Assistant native
• easy to customize

Hardware Overview

The controller board includes:

• ESP32 WiFi module
• 7 relay outputs
• 24VAC power input
• onboard AC-DC conversion
• USB port for firmware flashing
• terminal blocks for zone wiring

The design allows the board to sit directly inside an HVAC control panel or automation enclosure.

Smart HVAC Zoning With ESPHome

By combining this controller with ESPHome and Home Assistant, you can create advanced HVAC automation such as:

temperature-based airflow balancing
occupancy-based zoning
nighttime airflow reduction
seasonal HVAC profiles

This makes it possible to build fully automated smart HVAC zoning without proprietary hardware.

Final Thoughts

Home automation platforms like Home Assistant have revolutionized smart homes, but integrating traditional HVAC control systems has remained difficult.

This ESPHome 7-zone HVAC controller bridges the gap by allowing direct control of 24VAC HVAC dampers and valves.

No extra power supplies.

No complicated voltage conversions.

Just ESPHome-powered smart control for HVAC zoning.

ESPHome 7-Zone HVAC Controller – Smart 24VAC Zone Control for Home Assistant