How to install Themo wall thermostat?

Created by Themo Support, Modified on Sun, 18 Aug at 9:35 AM by Themo Support

Safety Precautions:


Please be aware of the following:

  • The installation of the thermostat should be conducted by an authorized and skilled technician in accordance with local regulations.
  • The thermostat must be linked to a power source through an all-pole disconnection switch.
  • Ensure that the thermostat remains connected to a continuous power supply at all times.
  • Avoid exposing the thermostat to moisture, water, dust, or excessive heat.
  • Ensure children are supervised to prevent them from playing with the thermostat.
  • Cleaning and user maintenance tasks should not be carried out by children without supervision.


Before proceeding with the installation, ensure that the main power supply to the thermostat is switched off.


It's crucial to note the following when using the thermostat to regulate a floor heating system in conjunction with a wooden floor or similar material: Always incorporate a floor sensor and refrain from setting the floor temperature above 35°C.


Mounting Instructions


1. Switch off power.


Switch off power to your heating equipment at your circuit breaker box. Verify that your existing thermostat should not be able to display any indication of operation.


2. Remove cover.

Remove the cover of your old thermostat to reveal the wiring. Most covers snap off easily but some may be attached by screws. Screws are most commonly hidden behind the adjustment button.


3. Label the wires.



Look at the wires coming out of the wall. Take a picture of the wires on your old thermostat to help you remember their alignment by colours. Use stickers to label the wires for correct connection to Themo.


If your old thermostat has more than one wire coming out from each connector, or you need additional help, contact service support.


4. Disconnect and trim wires



Disconnect the labeled wires from the old thermostat base and remove the base from the wall using a screwdriver. Pull the thermostat wires out as far as possible.


The exposed part of the wire should be trimmed between 1 cm and 1.5 cm. Ensure the exposed wire is straight.



Note: Do not disconnect any capped wires which connect the screen of the heating cable and the earth conductor of the power supply cable.


5. Reconnect wires.


Connect the Themo thermostat according to the connection diagram. If you are replacing an existing thermostat, use the stickers as a guide when inserting the wires into the Themo terminal blocks.



The wires from the wall should plug easily into the terminal blocks. Use a screwdriver to tighten the terminal screws. Fasten the thermostat firmly to a flush mounted wall box or an exterior wall box by driving the screws through the holes in each side of the thermostat.


Note: The screen of the heating cable must be connected to the earth conductor of the power supply cable using a separate connector (capped with wire nuts).


Carefully fit the thermostat to the in-wall socket and tighten the screws.


6. Attach front panel.

Add the frame before assembling the front panel to the base. Push the front panel in place. When connecting the front panel to the base, make sure that the female header will not bend the connectors. Press carefully until the front panel is fixed against the frame.


7. Switch on power.



Switch on the power to your heating equipment at your circuit breaker box. Watch Themo come alive!


See the video how to install Themo with floor sensor.




Was this article helpful?

That’s Great!

Thank you for your feedback

Sorry! We couldn't be helpful

Thank you for your feedback

Let us know how can we improve this article!

Select at least one of the reasons
CAPTCHA verification is required.

Feedback sent

We appreciate your effort and will try to fix the article