Guida al Termostato Intelligente SONOFF Zigbee: Installazione, Funzionalità e Domande Frequenti

Introduction

The SONOFF Thermostat Core (TP-WGZBA) is a Zigbee smart thermostat panel designed for hydronic underfloor heating and compatible boiler heating systems. It supports both powered and dry-contact control for compatibility with different heating systems, helping make home heating smarter, more flexible, and more comfortable.  

This guide covers smart thermostat installation, platform compatibility, wiring and setup, Italian 503 wall box installation, FAQs, and troubleshooting.

 

Compatible Zigbee Gateways and Platform Requirements

Home Assistant

Via Z2M

• The current device requires Zigbee2MQTT version 2.14.0 or higher. If not updated to this version or above, the device may fail to connect properly or may lack full functionality.

Via ZHA

• A pull request #5201 adds native ZHA support for SONOFF TP-WGZBA (Thermostat Core), but is not yet merged. Some features won't work out of the box. For full functionality now, manually configure it with the script: TP-WGZBA_ZHA_Script.zip

SmartThings

To connect directly to the SmartThings platform, you need to use a driver. For the driver download link and tutorial, see:

Tutorial: https://sonoff.tech/blogs/news/sonoff-products-integration-guide-for-smartthings-driver-installation

Drivers URL link: https://bestow-regional.api.smartthings.com/invite/OzMgP34LbA29

• Update the device to the latest firmware (V1.0.3)
• Update your Sonoff Zigbee Gateway to:
  • ZBBridge-P: V3.4.1 or higher
    • To use features linked with TRVs ("Thermostat Panel Control" in App settings), update ZBBridge‑P to firmware V3.5.0 (expected release in late September)
  • ZBBridge-U: V2.6.0 (Beta users: V3.9.0) or higher (expected release in early September)
  • NSPanel Pro / NSPanel Pro Gen2: V4.8.0 or higher
    • To use features linked with TRVs ("Thermostat Panel Control" in App settings), update the gateway to firmware V4.9.0 (expected release in late September).
  • iHost: V2.15.0 or higher (expected release in October)
  • Bridge-M: V1.2.0 or higher (expected release in late September)

🔔Upgrade your eWeLink App to V5.27.0 or higher

Smart Thermostat Installation Guide

Installation Video  

Watch the video below for a step-by-step guide to installing and wiring the SONOFF Thermostat Core TP-WGZBA.

Download and 3D Print the Italian 503 Adapter Base  

This 3D-printed adapter base is designed to install the SONOFF 86-type thermostat panel on 503-type wall boxes commonly used in Italy.  

👉 3D Printing File: Thermostat_Core_(TP-WGZBA)_3D‑printed_adapter_base.zip

The 3D printing files include:
● 1 × 503 wall box adapter base
● 2 × screw covers

Prepare separately

● 2 × M3 brass heat-set inserts
● 2 × M3 × 10 mm screws for securing the thermostat mounting base to the adapter base

Installation Steps

1. Install the brass heat-set inserts: Install the two M3 brass heat-set inserts into the designated holes.
2. Secure the adapter base: Use suitable screws to secure the adapter base to the wall box.
3. Install the screw covers: Install the two screw covers on the left and right sides of the adapter base to conceal the screws used to secure it to the wall box and create a cleaner finish.
4. Secure the thermostat mounting base: Position the thermostat mounting base in the center of the adapter base and align it with the installed brass heat-set inserts. Use two M3 × 10 mm screws to secure the mounting base to the adapter base.
5. Complete the installation: After completing the wiring according to the thermostat instructions, attach the thermostat panel to the mounting base. Make sure the device is securely installed before restoring power.

❗Note: Turn off the power before installation. Work involving mains wiring should be carried out by a qualified electrician.

 

 

 

FAQ

Q1: What heating systems is the Thermostat Panel compatible with?

The Thermostat Panel is designed for hydronic underfloor heating systems and boiler heating systems. It can control hydronic underfloor heating actuators or provide a dry contact signal for boiler control.

The relay output is rated for a maximum load of 3 A. As most electric underfloor heating systems exceed this rating, the Thermostat Panel is not suitable for direct connection to electric underfloor heating.

 

Q2: Can the Thermostat Panel control water underfloor heating actuators?

Yes. The Thermostat Panel can control compatible hydronic underfloor heating actuators.
Supported output ratings:

• 100–240 V AC, max. 3 A

By default, the Thermostat Panel uses Normally Open (NO) relay logic. When heating is required, the relay closes and activates the heating output. When heating is no longer required, the relay opens and stops the output.

This default setting is suitable for Normally Closed (NC) actuators.

If your hydronic underfloor heating system uses a Normally Open (NO) actuator, go to Heating System Settings in the eWeLink app and select NO actuator.

If you are unsure about the actuator type, check the product label or consult your heating installer.

 

Q3: What type of boiler control does it support?

The Thermostat Panel supports ON/OFF control for boilers with a normally open (NO), potential-free thermostat input.

When heating is required, the COM and NO terminals close to start the boiler. When heating is not required, the contact opens.

❗Note: COM and NO are potential-free contacts for boiler control only. Do not connect them to mains power.

 

Q4: Will schedules continue working if the Zigbee connection is disconnected?

Yes. The Thermostat Panel has a built-in real-time clock (RTC), and saved heating schedules are stored locally on the device. They will continue running even when the Zigbee connection is temporarily unavailable, provided that the thermostat remains powered.

 

Q5: Can I replace my existing thermostat directly?

It depends on your existing heating system.

Before installation, please check:

• The wiring of your existing thermostat
• Heating actuator specifications
• Boiler control method
• Whether the wall box is compatible with the thermostat’s installation dimensions

The Thermostat Panel requires a live wire (L), a neutral wire (N), and the appropriate control wiring for the connected heating device. If your existing thermostat has only two wires and there are no additional wires available in the wall box, it cannot be directly replaced using the existing wiring. A qualified electrician may be required to provide the necessary wiring.

If you are unsure about the wiring, consult a qualified electrician.

 

Q6: Do I need to configure the Heating System Settings in the eWeLink app?

By default, the Thermostat Panel uses Normally Open (NO) relay logic:

When heating is required, the relay closes and activates the corresponding heating control output.

When heating is no longer required, the relay opens and stops the output.

Therefore, the default configuration is suitable for:

• A Normally Closed (NC) actuator for hydronic underfloor heating
• A Normally Open (NO) contact for boiler control

If your hydronic underfloor heating system uses a Normally Open (NO) actuator, go to Heating System Settings in the eWeLink app and select NO actuator.

If your boiler requires a Normally Closed (NC) control contact, go to Heating System Settings and select NC boiler.

If you are unsure about the actuator type or boiler control type, check the product label or boiler manual, or consult your heating installer.

 

Q7: Is an external temperature sensor required?

No. The Thermostat Panel can be used with its built-in temperature sensor by default.
An external sensor is optional. If required by your heating system, you can connect a compatible NTC 10 kΩ, β = 3950 sensor to monitor floor temperature.

 

Q8: Can the Thermostat Panel be installed on an Italian 503 wall box?

The Thermostat Panel requires an adapter for installation on the 503-type wall boxes commonly used in Italy. You can download the file and make the adapter using a 3D printer, or use a compatible commercially available adapter. 

 

 

 

Troubleshooting

1. The heating does not turn on.

Possible Causes:

• The target temperature has not reached the heating start threshold.
• The temperature hysteresis setting prevents the heating from starting immediately. 
• The heating system behavior settings in the app do not match the connected actuator or boiler.
• The actuator or boiler wiring is incorrect.
• The actuator specification is not supported.
• The thermostat is not detecting a heating demand.

Solutions:

• Check the target temperature setting and confirm whether heating should be activated.
• Check the temperature hysteresis setting in the app and confirm the heating start threshold.
• Confirm that the Underfloor Heating Valve Behavior and Boiler Control Contact Behavior settings match your actual heating system.
• Check the actuator and boiler wiring.
• Confirm actuator specifications:
  • 100-240V AC, up to 3A
• Confirm that the actuator and boiler are working properly.

 

2. The heating does not stop after reaching the target temperature.

Possible Causes:

• The temperature reading is inaccurate.
• The heating system behavior settings in the app do not match the connected devices.
• The actuator and boiler do not close properly.
• The thermostat is still detecting a heating demand. 

Solutions:

• Check whether the displayed temperature is accurate.
• Confirm that the Underfloor Heating Valve Behavior and Boiler Control Contact Behavior settings match your actual heating system.
• Check whether the actuator and boiler open and close properly.

 

3. The heating system works in the opposite way.

Example:

• Heating turns off when it should turn on.
• Heating stays on when it should turn off. 

Solutions:

• Check whether the displayed temperature is accurate.
• Confirm that the Underfloor Heating Valve Behavior and Boiler Control Contact Behavior settings match your actual heating system.
• Check whether the actuator and boiler open and close properly.