WiFi thermostat PNI CT400 for boiler control via Tuya Smart app

Product detailed description

PNI CT400 is a wireless smart thermostat that turns the boiler or heat pump on and off according to the room temperature measured. It connects to the home WiFi network, so you can control it directly on the device or from your smartphone using the Tuya Smart or Smart Life app. In the documentation, the model is occasionally listed under the designation PNI CT40 PRO.

The set consists of a control unit with a display and a receiver unit. The receiver is connected to the control circuit of the heating appliance, and the control unit can be placed on a table or mounted on a wall. Communication between the two units takes place via radio at 868 MHz, and the thermostat connects to the router via WiFi 802.11b/g/n in the 2.4 GHz band.

Main Features

• Heating and cooling mode: the desired room temperature is maintained regardless of the season.
• Smartphone control: you can turn the device on or off, change the temperature, adjust settings, create a schedule, and monitor operation via the app.
• Fine regulation: hysteresis can be adjusted in the advanced menu from 0.1 °C to 0.6 °C, so the room temperature fluctuates minimally.
• Programmable operation: up to 4 daily schedules, which can be set on the thermostat or in the app.
• Manual mode: you can start or stop heating manually at any time.
• Protection functions: child lock (key lock), open window detection, and anti-frost protection.
• Large backlit display with clearly readable characters.

How the thermostat works

Hysteresis determines the difference between the temperature at which the thermostat turns heating on and the temperature at which it turns it off. The smaller the hysteresis, the more even the room temperature, but the device switches more frequently. That is why it is useful that you can set the value according to your preferences.

Open window detection quickly detects heat loss during ventilation and adjusts the heating system operation. Anti-frost protection ensures a minimum temperature to prevent damage to the installation in winter. The child lock prevents accidental changes to the set temperature.

Technical Specifications

Control Unit

• powered by two 1.5 V alkaline batteries (not included in the package) or via USB-C (5 V, 1 A)
• the measured room temperature, set temperature, current time, current schedule, and wireless connection status are visible on the display
• can be mounted on the wall or placed on a table

Receiver Unit

• mounted on the wall, powered by 230 V AC, 50/60 Hz
• communication: WiFi 2.4 GHz with the router, radio 868 MHz with the control unit, cable with the central heating
• zero-voltage (no-voltage) relay NO/NC, two multifunction buttons, and two LED indicators showing the status
• can close a classic NO control circuit of the heating appliance if its parameters match the relay

Usage and Installation

The thermostat is universal and not tied to a specific boiler brand. Before connecting, make sure that the control input of your device matches the relay parameters. Since the receiver is connected to the 230 V network, the installation should be carried out by a qualified person.

Package Contents

• control (central) unit
• receiver unit
• wall mounting bracket and table stand
• mounting screws

Frequently Asked Questions

Can heating be controlled from a smartphone?

Yes. The thermostat is compatible with the Tuya Smart app, where you can change the temperature, adjust the schedule, and turn heating on or off remotely.

Can I set the schedule directly on the thermostat?

Yes, 4 daily schedules can be set on the device itself as well as in the app.

Are batteries included in the package?

No, batteries for the control unit must be purchased separately. The unit can also be powered via USB-C.