K9 WiFi Smart Thermostat with Colour Touchscreen and Voice Control

Overview

The SunAura K9 is a WiFi smart floor-heating thermostat built around a bright colour touchscreen, designed to control the three most common hydronic and electric heating systems found in modern homes: water underfloor heating, electric underfloor heating (heating film, cable, mat and wall warming panels), and wall-hung gas boilers switched through a dry-contact output. At 86×86×13 mm in a flame-retardant wall box, it fits the standard European and Chinese 86 mm mounting grid, and is offered in black or white to match any interior finish.

Beyond the touchscreen, the K9 connects to your home WiFi network and a Tuya-compatible smart home app, so you can set a weekly heating schedule, pre-heat rooms before you arrive, switch between manual, automatic and energy-saving modes, lock the unit against children, and check or change the temperature from anywhere using your phone. Hands-free voice control is built in and works with Alexa, Google Home and Yandex Alice smart speakers, so the room temperature adjusts simply by asking.

For installers and distributors, the K9 is offered as three hardware variants matched to the load: a 3 A plumbing/boiler version with a dry-contact output for gas boilers and NC/NO zone actuators, and 16 A or 25 A versions for direct-switching electric underfloor heating (the 25 A model uses the reinforced K9H25A backplate). A RS485 version is available for centralised building management. Every K9 carries CE certification and IP20 enclosure rating, and ships from the SunAura Thermal factory in Qingdao.

Key Features

• Colour touch LCD, no physical buttons to wear out — a responsive glass touch surface with MODE, TIME, power and +/− keys rendered on screen, showing room temperature, set temperature, humidity, weather icons, WiFi status, heating flame, HOME and night mode and the clock.
• Full app and remote control — pair the K9 with a Tuya-compatible app over 2.4 GHz WiFi to set weekly schedules, adjust temperature, switch modes and review running status from a phone, anywhere in the world.
• Works with voice assistants — hands-free temperature control through Alexa, Google Home and Yandex Alice, using the same Tuya-compatible app and voice assistants you already use around the home.
• True weekly programming — separate weekday and weekend programmes with up to six time periods per day, each with its own target temperature, so heating follows your family routine instead of running around the clock.
• Three load variants for the whole heating plant — 3 A dry contact for water underfloor heating and wall-hung gas boilers, 16 A for typical electric film and mats, and 25 A (K9H25A backplate) for higher electric loads; RS485 central control on request.
• High-temperature fire protection and safety design — flame-retardant housing, over-temperature shut-off, child lock and adjustable screen brightness for safe, comfortable daily operation.
• Temperature calibration −9 to +9 °C — offset the displayed reading against a reference thermometer so the set-point matches reality, compensating for wall height, sensor position or floor build-up.
• Manual / automatic / energy-saving modes — run a fixed comfort temperature, follow the weekly programme, or drop to an energy-saving set-point when the room is empty or at night.
• Power-off memory — schedules, calibration and mode settings are retained through a power cut, so the heating system resumes normal operation without re-commissioning.

Display & Icon Guide

The K9 colour screen is designed to be read at a glance. The large ROOM reading is the measured room temperature; the smaller SET reading is the target temperature you have programmed, so the two are never confused. A humidity percentage is displayed alongside the temperature, and simple weather icons give a quick visual cue of outdoor conditions pulled through the app.

Status icons light up as the system runs: the WiFi icon confirms cloud connection, the heating flame icon shows when the output is energised and the boiler, valve or floor heater is actually calling for heat, the HOME icon marks comfort mode, and the moon icon marks the night / energy-saving period. The clock runs in 24-hour format and anchors the six daily time periods of the weekly programme.

Touch keys sit along the bottom of the screen: MODE switches between manual, automatic, energy-saving and holiday operation, TIME opens the clock and scheduling settings, the power key turns the output on or off without unplugging the unit, and +/− adjusts the set temperature directly. The child lock removes on-screen key response, while the app remains fully operable.

Technical Specifications

Applications

Because the K9 covers three hardware load classes from the same touchscreen platform, one thermostat family can run the complete heating plant of a project:

• Water underfloor heating — the 3 A version switches the boiler call and drives NC/NO zone actuators on a radiator or underfloor manifold, keeping each room on its own schedule.
• Wall-hung gas / wall-hung boilers — the dry-contact output replaces a traditional room thermostat, giving the boiler a clean on/off call signal without touching the boiler’s internal wiring.
• Electric underfloor heating — the 16 A or 25 A versions switch the load directly, driving graphene heating film, heating cables, heating mesh mats and decorative wall warming panels (heating paint / infra-paint panels).
• Renovation and smart-home retrofits — replacing an old mechanical thermostat box-for-box with a K9 adds app and voice control to an existing hydronic or electric system.

Installation

The K9 mounts into a standard 86 mm flush wall box. The front cover clips off to expose the screw terminals, the unit is fixed to the back box, and the cover snaps back on once power is restored and the WiFi pairing is complete. All mains connections must be carried out by a qualified electrician with the supply isolated.

1. Water / boiler (3 A) version — connect live and neutral (L/N) of the AC supply to the power terminals; wire the NO/NC dry contact output to the wall-hung gas boiler’s external thermostat terminals and to the NC/NO zone actuators on the manifold. The dry contact is volt-free, so it is safe to wire alongside low-voltage valve signals.
2. Electric (16 A / 25 A) version — connect L/N mains input to the supply terminals and the heating load to the output terminals; the line and neutral of the load are not polarity-sensitive. Run the optional external NTC floor limit probe into the floor build-up (beneath film or cable) so the K9 can switch off if the floor surface overheats.
3. Pairing — after power-on, open the Tuya-compatible app, add device, select the thermostat category and follow the on-screen WiFi pairing steps; assign rooms, set the weekday/weekend schedules and link the voice-assistant skill in the app.

Compatibility with SunAura Heating Systems

The K9 is the control layer for the full SunAura Thermal heating range. Pair the 3 A version with SunAura water underfloor manifolds, zone actuators and wall-hung boilers; pair the 16 A / 25 A versions with SunAura graphene heating film, double-conductor heating cables, heating mesh mats and infrared wall warming panels. When you order heating elements and K9 thermostats together from SunAura, we can pre-set the temperature limits, floor-sensor thresholds and weekly programme to match your floor build-up, and ship a complete kit — heater, thermostat, insulation, probes and wiring accessories — from one factory source with one warranty.

For larger projects, the RS485 option lets multiple K9 units integrate into a centralised building control system, and OEM/ODM customers can request custom housing colours, private-label packaging and branded app pairing.

Quality, Certification & Support

SunAura Thermal has manufactured heating controls and electric heating products since 2008 from our Qingdao factory, operating with ISO-style quality management and 100% in-line QC testing on every thermostat batch before shipment — every K9 leaves the factory marked QC PASS. The product family carries CE certification and an IP20 indoor enclosure rating, and documentation is available for importer and distributor compliance files.

With more than 17 years of OEM/ODM experience, SunAura exports heating thermostats and heating elements to 50+ countries, supporting distributors and installers with English, German, French and Chinese after-sales guidance, spare parts, remote commissioning by WhatsApp, and a standard 2-year warranty on every K9 unit.

FAQ

1. Which version should I buy — the 3 A, 16 A or 25 A K9?

Choose by what the K9 has to switch. The 3 A dry-contact version is for water underfloor heating and wall-hung gas boilers: it does not switch the heater itself, it gives the boiler or zone actuators a volt-free on/off signal. The 16 A version switches electric underfloor heating directly for typical film, cable and mat loads up to about 3,500 W. If the electric load exceeds 16 A, use the 25 A (K9H25A backplate) version. When in doubt, send us the total wattage of your heater and we will confirm the correct SKU before shipping.

2. How do I pair the K9 with the app and WiFi?

Power the unit on, open the Tuya-compatible smart app, tap “Add Device”, choose the thermostat category and follow the on-screen steps to connect to your 2.4 GHz WiFi network. Once paired, you can set weekly schedules, adjust temperatures, switch modes and enable voice control from the app. The K9 supports 2.4 GHz WiFi only; if your router broadcasts a combined 2.4/5 GHz network, pairing still works on the 2.4 GHz band.

3. Does the K9 work with Alexa, Google Home or Yandex Alice?

Yes. The K9 works with Tuya-compatible app and voice assistants. Link the Tuya-compatible skill in your Alexa, Google Home or Yandex Alice app, discover the K9 as a thermostat device, and you will be able to set the room temperature by voice.

4. What happens to my schedules and settings during a power cut?

All settings — weekly programme, calibration, mode and child lock — are stored in non-volatile memory. When power returns, the K9 boots back into the same programme and set temperature automatically, with no re-pairing or re-programming required.

5. Do I need an external floor sensor?

For the electric underfloor versions, we strongly recommend running the external NTC floor limit probe beneath the heating film or cable. It lets the K9 monitor the actual floor temperature and cut out if the surface gets too hot, which protects the floor covering and meets installation norms. The water/boiler version uses the internal room sensor and the boiler’s own safety controls.

6. Can the display temperature be calibrated if it reads a little high or low?

Yes. In the device menu or app, set a calibration offset between −9 °C and +9 °C. Place a reference thermometer next to the K9, let both settle for a couple of hours, and offset the K9 reading to match. Typical corrections are small (±1–2 °C) and compensate for wall height or sensor position.

7. Is installation difficult and can a homeowner fit it?

The K9 clips into a standard 86 mm wall box and pairs with the app like any smart device, but the mains wiring itself must be done by a qualified electrician with the supply isolated — especially the 16 A/25 A load terminals, which carry full heater current. A wiring diagram ships in the box, and our engineers can walk an installer through commissioning by WhatsApp in English, German, French or Chinese.

8. What is the warranty and after-sales support?

Every K9 includes a 2-year warranty from SunAura, covering manufacturing defects. We support installers and distributors directly — configuration help, replacement parts, remote commissioning and compliance documents (CE, QC PASS) — with replies typically within one business day.

How to Buy the K9 — Wholesale, OEM & Factory-Direct

Specifying a smart thermostat with Alexa, Google Home and Yandex Alice for hydronic and electric underfloor heating across a residential or light-commercial project? The SunAura K9 covers the whole heating plant from one colour-touch platform: a 3 A dry-contact version for water underfloor heating and wall-hung gas boilers, 16 A and 25 A (K9H25A backplate) versions for direct electric film, cable and mat loads, and an RS485 central-control thermostat option for building-management integration. Installers, heating distributors and private-label brands buy the K9 factory-direct from our Qingdao ISO-managed plant, with CE certification, IP20 enclosure rating and QC PASS on every unit. We quote every enquiry the same working day.

Because the K9 pairs with the Tuya-compatible app over 2.4 GHz WiFi and links the same voice-assistant skill to Alexa, Google Home and Yandex Alice, it drops into smart-home setups your customers already own — while the on-screen touch keys, power-off memory and −9 to +9 °C calibration keep it behaving like a serious heating controller even away from the phone. OEM customers can request black or white housings, private-label packaging and custom app-pairing flows.

To order, tell us the variant per room (3 A dry-contact for water/boiler, 16 A or 25 A K9H25A for electric loads, RS485 for central control), whether you need the external NTC floor-limit probe, the quantity and your destination port. Contact our sales team with your load list, or message us on WhatsApp for a same-day reply. Browse the full controller lineup on the thermostats and controls category page, and see multi-zone K9 installations in our applications gallery.

RS485 Multi-Room Projects

For apartment blocks, hotels and light-commercial projects where each room needs its own schedule but the building engineer wants central visibility, the RS485 version of the K9 lets multiple units integrate into a centralised building control system alongside the on-device touchscreen and app experience. Pair the 3 A version with hydronic manifolds and wall-hung boilers, and the 16 A / 25 A versions with SunAura graphene heating film, heating cables and mesh mats for a single-vendor heating plant.

For single-family homes that want the same voice and app experience without RS485, the K2M dual-version WiFi floor-heating thermostat is the value SKU on the same 86 mm wall box, while the K1M WiFi thermostat with colour LCD and antifreeze mode suits budget-conscious bedrooms. Simple wired guest rooms can use the K1 non-WiFi programmable thermostat. More ordering, RS485 and commissioning questions are answered on the thermostat FAQ page.

9. How does the RS485 central-control option work for multi-room projects?

The RS485 version of the K9 adds a wired bus alongside the on-device touchscreen and WiFi app, so multiple K9 units on one site can report room temperatures, schedules and fault states to a central building controller. This is typically specified for hotels, apartment blocks and light-commercial projects where the facilities team wants room-by-room visibility without opening each unit’s app. Ask for the RS485 SKU when you send your enquiry.

10. Can the K9 be used as a thermostat for hydronic underfloor heating with a gas boiler?

Yes — the 3 A dry-contact version is purpose-built for this. Its volt-free NO/NC output gives the wall-hung gas boiler a clean on/off call signal and drives NC/NO zone actuators on the manifold, without touching the boiler’s internal wiring. The internal room sensor controls the schedule; the boiler’s own safety controls remain in place.

11. Do you offer bulk pricing and private-label branding for K9 thermostats?

Yes. SunAura exports K9 units to 50+ countries under both our own brand and private labels for heating distributors and installers. Bulk discounts, MOQ and lead time depend on the mix of 3 A, 16 A, 25 A and RS485 SKUs — send your load list and target markets, and we will reply with a same-day EXW / FOB quotation, sample policy and OEM packaging options.

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