Baxi-Usense-Wired-Smart-Thermostat-PRODUCT - Copy

Baxi Usense Wired Smart Thermostat Installation Guide


Baxi Usense Wired Smart Thermostat



The Baxi uSense Wired Smart Thermostat is compatible with all combi boilers using the 230V switched live and also has OpenTherm capability.
Warning: High Voltage wiring must only be installed and worked on by a suitably qualified person.

In the boxBaxi-Usense-Wired-Smart-Thermostat-FIG-1

Room unit package:

  1. User guide
  2. Room unit
  3. Screw and plug fixings
  4. Mounting bracket

Gateway package:

  1. The gateway
  2. Installation guide
  3. Screw and plug fixings
  4. 230V power adaptor
  5. Adhesive pad for power adaptor

Before you start

Wear appropriate Personal Protection Equipment e.g. protective gloves, safety footwear etc.Baxi-Usense-Wired-Smart-Thermostat-FIG-2

Positioning the uSense:
The room unit must be positioned taking into account the following factors:

  • On an internal wall
  • Away from draughts
  • 1.2-1.5m from the floor
  • Not behind doors, bookcases or other objects
  • Not in direct sunlight
  • In a room where the user spends most of their time
  • Away from heat sources (fireplace, radiators, light, candles, etc.)
  • The maximum cable length from the gateway to the room unit is 50m

Prior to installation make sure to

  1. Isolate the power to the heating and control system and make safe (remove or lock off fuse)
  2. Check that the power has been isolated using suitable test equipment.

Warning: High Voltage wiring must only be installed and worked on by a suitably qualified person.


The gateway
When connecting the gateway to a combi boiler that has an existing programmer and/or thermostat, it is essential that the function of all wiring is established prior to work. Make sure you identify the L (live), N (neutral), E (earth), common and call for heat switched live correctly before connecting. Incorrect wiring will result in damage to the gateway, room unit and boiler which will invalidate the warranty.

Fix the gateway in position
Determine the position of the gateway. It should be close to either the boiler or control system junction box. Make sure there is enough space around the gateway for installation and maintenance, including screwdriver access.

Run power to the gateway
Use the power adaptor supplied to connect the gateway to the L (live) and N (neutral) connectors on the boiler or junction box. Connect the plugged end of the power adaptor into the 24V terminal on the gateway.Baxi-Usense-Wired-Smart-Thermostat-FIG-3

  1. All cables must be supported
  2. The power adaptor and wiring must not be inside the boiler
  3. The power adaptor must be supported (adhesive pad is supplied for this).

Installation of 230V switched connection (See next page if using OpenTherm)

Connect the system control wiring to the gateway
Read in conjunction with the boiler installation and service manual

  • Gateway terminals – ON/OFF are for 230V switching
  • Gateway terminals – OT are for OpenTherm connection to compatible boilers
  • Gateway terminals – R-BUS are for connection to the uSense room unit

WARNING:  These components are low voltage – 230V will damage the room unit and gateway.

To connect using the ON/OFF terminalsBaxi-Usense-Wired-Smart-Thermostat-FIG-4

  1. Connect the common from the boiler or junction box to the ON terminal on the gateway.
  2. Connect the switch live terminal or junction box to the OFF terminal on the gateway
  3. The cable used must be 0.75mm multi strand flexible cable conforming to BS 50525-2-11.

Installation of OpenTherm connectionsBaxi-Usense-Wired-Smart-Thermostat-FIG-5

To connect using the OT terminals

  1. Connect the OpenTherm connectors on the boiler to the OT terminals on the gateway D o not connect 230V to these terminals or it will damage the gateway
  2. These will communicate with the boiler to control the heating and other functions
  3. These connections can be made using bell wire. There is no polarity at the OT terminals.

To connect the gateway to the uSense using the R-BUS terminals

  1. Choose a suitable location for the uSense thermostat (see Before you start section on page 5)
  2. Remove existing thermostat (if applicable)
  3. Fix the room unit backplate to the wall using the screws provided
  4. Either use existing thermostat wires or run new wires from the gateway  (there is no polarity – either wire can be connected to either position)
  5. Trim the wires coming out of the wall, connect them into the connector block on the room unit backplateBaxi-Usense-Wired-Smart-Thermostat-FIG-6
  6. Slacken the screws at the sides of the connectors and insert each wire into the top at either side of the connector, then re-tighten the screws
  7. Make sure the wires are as flat as possible against the back plate so that they do not interfere with the controller when it is mounted in position
  8. Press the room unit onto the backplate until it clicks into place
  9. Connect the other end of the wires
    to the R-BUS terminals in the gateway
    (there is no polarity – either wire can be connected to either position)
  10. The connection between the room unit and gateway is low voltage, 230V will damage the room unit and gateway!Baxi-Usense-Wired-Smart-Thermostat-FIG-7

Set up the uSense room unit
Before turning on the power to the gateway, room unit and heating system, preliminary electrical tests should be carried out.

  1. These should be carried out using a suitable meter, and include checks for earth continuity, resistance to earth, short circuit and polarity
  2. Turn on the power to the gateway and check that the gateway and room unit power up. See page 19 for LED key
  3. Download the Baxi uSense Smart Thermostat App and create a uSense account
  4. Use the user guide (supplied) to set up uSense.

OpenTherm hot water control

The uSense room unit will override the hot water temperature controls on your combi boiler (OpenTherm only).Baxi-Usense-Wired-Smart-Thermostat-FIG-8

  1. The room unit will automatically default the hot water temperature to 60°C when connected by OpenTherm
  2. The room unit will automatically default the heating flow temperature to 80°C when connected by OpenTherm
  3. These settings can be adjusted to your required comfort level using the uSense room unit only (the boiler controls and App can’t adjust these settings
    when the room unit is connected with OpenTherm).

Outdoor sensor

Connecting to an outdoor sensor
If an outdoor sensor weather compensator is connected in conjunction with the uSense (OpenTherm installations only) you can ONLY adjust the heating curve on the uSense App (you CANNOT adjust using the room unit or boiler controls).

  1. Open the Baxi uSense App
  2. Click on the installer menu
  3. Click on advance settings
  4. Enter service code 0012 Remember to re-enter this code to disable installer access when you finish adjusting the heating curve
  5. You will see a message ‘Your access level has been updated’
  6. Click OK
  7. Click on heating curve
  8. Change the curve to suit the requirements of the user in accordance with the recommendations of the sensor manufacturer
  9. Do not adjust any other settings in the Advanced Feature menu,  as they may affect the correct operation of the boiler
  10. Either completely close the App or re-enter the code to cancel the access level so that your customer can’t adjust important settings.

Technical specifications

uSense room unit

Baxi-Usense-Wired-Smart-Thermostat-FIG-9 Baxi-Usense-Wired-Smart-Thermostat-FIG-10 Baxi-Usense-Wired-Smart-Thermostat-FIG-11 Baxi-Usense-Wired-Smart-Thermostat-FIG-12

Gateway LED key

The LED on the gateway indicates the following modes and faults


  • Starting up
  • Gateway in operation
  • No boiler detected (check connections and wiring)
  • No room unit detected (check connections and wiring)
  • Internal error (turn all power off, reinstate and perform setting procedure again)

Warranty registration

  • For the parts warranty to be activated and maintained, please register the uSense Smart Thermostat at:
  • Please note: if you do not register the warranty, a basic 12 month warranty will apply.
  • For full terms and conditions visit
  • Please ensure the uSense is installed in accordance with these installation instructions and that you adhere to the Building Regulations. e&oe

QR SCANBaxi-Usense-Wired-Smart-Thermostat-FIG-14

All descriptions and illustrations provided in this document have been carefully prepared but we reserve the right to make changes and improvements in our products which may affect the accuracy of the information contained in this booklet. All goods are sold subject to our standard Conditions of Sale which are available on request.

For technical support call 0344 871 1545

For tech support
0344 871 1545
Opening hours
Monday – Friday, 8.00am-6.00pm
Weekends and Bank Holidays, 8.30am-2.00pm
Please note calls may be recorded for training and monitoring purposes
Brooks House, Coventry Road, Warwick. CV34 4LL



Baxi Usense Wired Smart Thermostat Installation Guide


Baxi Usense Wired Smart Thermostat User Guide


Baxi Usense Wired Smart Thermostat User Guide





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