Sonoff Thermostat Core Review: A Local-First Zigbee Thermostat With a Real Dial
The Sonoff Thermostat Core (TP-WGZBA) is a flush-mount Zigbee thermostat for water underfloor heating and boilers, built for homes that already run a Zigbee coordinator. Its standout is that it runs locally: the weekly schedules live on the unit, so the heating keeps working even when the network or the smart-home hub is down, and the physical dial makes day-to-day changes easy without a phone. Home Assistant users get deep control over Zigbee2MQTT, and the radar-woken display, external temperature source and open-window detection round out a well-equipped, budget-tier unit. The catch is the familiar Zigbee one: it needs a hub and mains wiring, and ZHA support is not on par with Zigbee2MQTT yet.
- Zigbee and Home Assistant homes
- Water underfloor heating
- Boiler control
- Local-control advocates
Pros
- Schedules stored on the device, so the heating keeps working without the cloud or the hub
- Deep scheduling: three weekly plans with up to 12 temperature periods a day
- Physical rotary dial plus a radar-woken LED display that sleeps when you leave
- Works with Home Assistant through Zigbee2MQTT (a recent version is required)
- Supports an external temperature source, temperature offset, open-window detection and frost protection
- Dual output: a 3 A relay for water heating actuators and a potential-free COM/NO dry contact for boilers
- Works with Alexa, Google Home and SmartThings, and reaches Apple Home through a Sonoff Matter bridge
Cons
- Zigbee end device: a compatible hub is required, and there is no Wi-Fi or standalone app control
- ZHA support lags Zigbee2MQTT; native support is still pending and needs Sonoff's setup script
- The 3 A output is not suitable for directly switching high-power electric underfloor heating
- Requires a neutral wire and mains wiring, so installation is best left to someone confident with it
- No occupancy learning or cooling control, and no built-in speaker or microphone
Who is the Sonoff Thermostat Core for?
This is a wall-mounted thermostat panel for hydronic underfloor heating systems and boilers, not a replacement for a high-power electric underfloor mat. It fits a home that already has a Zigbee coordinator (a Sonoff gateway, a dongle, or a Zigbee2MQTT or ZHA setup in Home Assistant), because on its own it does nothing beyond acting as a manual thermostat. It suits two jobs in particular: driving water underfloor heating actuators through its relay output, and switching a boiler through the potential-free COM/NO dry contact, which is why one panel can manage an underfloor zone and a boiler together. Anyone replacing a dumb room thermostat with a wired dial will find the physical knob and the local schedules a better fit than an app-only thermostat, provided the wall box has a neutral wire.
What buyers love
Owners consistently highlight how local and self-contained the unit is: the weekly schedules are stored on the thermostat itself, so the heating keeps running as configured even if the internet or the smart-home hub goes down. Home Assistant users rate the Zigbee2MQTT integration highly, describing quick pairing and a rich set of entities for setpoint, current temperature and mode, and several use it to build presence- and window-aware automations. The physical dial draws repeated praise as a welcome change from tapping a touchscreen, and the radar sensor that wakes the display on approach and lets it sleep afterwards is called a genuinely pleasant detail. Buyers also like the depth of scheduling (three plans, up to 12 periods a day), the external temperature source for rooms where the panel's own position misreads the temperature, open-window detection, frost protection and the adjustable temperature offset.
What to know before you buy
The thermostat is a Zigbee 3.0 end device: without a compatible hub it is only a manual thermostat, there is no Wi-Fi fallback, and it needs a neutral wire in the wall box. It is designed for water systems, and its switched output is rated at 3 A, so it is not meant to switch a high-power electric underfloor heating load directly; control a boiler instead through the dry contact. On the software side, Zigbee2MQTT needs to be on a recent version for full support, and ZHA is behind it: native support is still a pending pull request, so ZHA users need the setup script Sonoff publishes and may find some features missing. A few buyers also mention that the app menus take some getting used to, and that the plastic housing feels more basic than the product photos suggest.
Is the Sonoff Thermostat Core worth it?
For a Zigbee household it is a strong value pick. The combination of a local-first design, three deep weekly schedules, a physical dial, radar display wake, external sensor support and boiler plus actuator outputs is a lot for the price, and it slots cleanly into Home Assistant through Zigbee2MQTT. What you give up against pricier thermostats is convenience and autonomy: no built-in Wi-Fi or cloud app for people without a hub, no occupancy learning, no cooling control, and a hub requirement plus mains wiring that raise the real setup cost. If you already run Zigbee and want your heating to keep working locally, it is an easy recommendation; if you want a plug-and-play thermostat with no hub, look elsewhere.
Frequently asked questions
Does the Sonoff Thermostat Core need a hub?
Yes. It is a Zigbee 3.0 end device, so it needs a compatible Zigbee coordinator such as a Sonoff ZBBridge, iHost or NSPanel Pro, a SmartThings hub with the Sonoff driver, or a Zigbee2MQTT or ZHA coordinator in Home Assistant. Without a hub it only works as a manual thermostat.
Does it work with Home Assistant?
Yes, and it is one of its strongest points. It works over Zigbee2MQTT, which Sonoff says needs to be a recent version for full support; with ZHA, native support is still a pending pull request, so some features need the setup script Sonoff publishes.
Can it control a boiler as well as underfloor heating?
Yes. It has a switched relay output (up to 3 A at 100-240 V) for water underfloor heating actuators and a separate potential-free COM/NO dry contact for a boiler, so it can drive both from one panel.
Does it keep working if the internet or the hub goes down?
Yes. The weekly schedules are stored on the thermostat itself, so the heating keeps running as configured even if the network or the smart-home system is unavailable.
Can it use a temperature sensor in another room?
Yes. It supports an external temperature source so the reading can come from a separate Sonoff sensor rather than the panel's own position, and it also has a temperature offset for calibrating the built-in reading.
What heating systems is it compatible with?
It is designed for hydronic (water) underfloor heating and boiler systems. Its 3 A output is not intended for directly switching high-power electric underfloor heating, which draws more than the relay can handle.



