How to Install Themo DIN Device

Created by Themo Support, Modified on Sun, 11 Aug at 1:35 PM by Themo Support

Safety precautions:


Please be aware of the following:

  • The installation of the device should be conducted by an authorized and skilled technician in accordance with local regulations.
  • The device must be linked to a power source through an all-pole disconnection switch.
  • Ensure that the device remains connected to a continuous power supply at all times.
  • Avoid exposing the device to moisture, water, dust, or excessive heat.
  • Ensure children are supervised to prevent them from playing with the device.
  • 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 device is switched off.


When Themo T700DIN is used to control the floor heating element in connection with a wooden floor or similar material, always use a floor sensor and never set the floor temperature to more than 30°C.


Important! Do not attach temperature sensor during installation and configuration
phase if Themo is to be used in PriceSwitch mode. Learn more about PriceSwitch


Important! For connecting higher loads than 3000W it is recommended to use
contactor. Read more about choosing right contactor


Important! When using a non-silent contactor, it might be required to use
RC snubber. Read more about choosing right contactor


Mounting instructions


1. Switch off power.


Make sure the mains supply to Themo T700 DIN location is turned off before installation! 


2. Power supply

The electrical diagram on the side of the device shows the relay connection diagram. Connect Themo T700DIN according to the connection diagram.


Note! Themo T700DIN main operation voltage is 230V


3. Relay operation

3.1 Controlling 230V AC supply

For 230V relay operation, use a jumper wire (included in the box). The jumper wire is to be connected into the two middle connection screws on the bottom connector



3.2 Controlling 24V supply

For 24V (or other low voltage) relay operation, connect a power supply with the wanted voltage through two lower left connection screws on the bottom connector (see picture). Do not use jumper wire.


3.3 Controlling dry contacts

For dry contact relay operation use two lower left connection screws on the bottom connector (see picture). The output of Themo T700DIN is a dry contact. Do not use jumper wire.




4. Relay rated load

The Themo T700DIN relay rated load is 16A @ 250VAC (24VDC), however the manufacturer recommended maximum load is 12A @ 250VAC (24VDC). For controlling electrical loads higher than 3000W with Themo T700DIN it is recommended to use contactor. Learn more about choosing right contactor.


Themo can measure the output when powered on. However when contactor is used then the power measurement is incorrect. To set the correct value after installation please follow this guide.


Note! If higher than 3000W load is connected to Themo T700DIN, it might be necessary to update your device firmware. Contact Themo support via support@themo.io to update firmware and allow Themo to operate correctly with high electrical loads.


5. Temperature sensor

To use Themo T700DIN in Thermostat mode, it is required to attach the temperature sensor before the configuration phase in the mobile application.


To use Themo T700DIN in PriceSwitch mode, it is required that the temperature sensor is NOT attached during the configuration phase in the mobile application.


Important! With PriceSwitch temperature input will not be used to control Themo. Therefore, it is not allowed to use the Themo T700DIN PriceSwitch mode to control any heating device that does not have its own internal thermostat to protect against overheating and fire hazard!



6. Contactors, fans, motors and other inductive loads

It is recommended to use a contactor if the electrical load connected to Themo exceeds 3000W. However, contactors, relays, fans, motors and other inductive loads may produce voltage spikes when turning off the load that are strong enough to harm Themo and cause unreliability. 


An RC Snubber is required to be installed over the load to reduce these spikes. The RC snubber is installed between the phase and neutral of the load (L Load and N Load on Themo or A1 and A2 on contactor). 


So called ”silent” contactors are less likely to cause problems, as they have similar electronics embedded. 

Hager ESC/ETC425S; ESC/ETC225S and ABB ESB16-20N contactors have been tested to work without an RC snubber.


7. Configuration.


Themo T700DIN must be set up properly through the mobile app to work safely. Download Themo mobile app to create a free account and follow step-by-step instructions on screen to set up your device. Until set up is done, some functions of Themo T700DIN might not work properly.






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