Written by Daniël
Edited on
8 July 2025
·
09:23
Advice on the connection of your thermostat
A boiler has different connectors for your thermostat wires. In this article, we'll explain how to replace your thermostat. This way, you can correctly connect your new thermostat.
Replace your thermostat in 5 steps
You'll work with power cords during the installation. Make sure you follow the steps from the manual of your boiler and thermostat correctly. We'll help you with the following steps:
- Step 1: check your power grid
- Step 2: turn off the AC power
- Step 3: connect your adapter
- Step 4: connect your thermostat
- Step 5: install the thermostat
Step 1: check your power grid
A boiler works on the power grid. That also applies to a thermostat. The thermostat receives its power via the boiler. When you connect a 24V thermostat to the 230V clamp, the wires of the thermostat will burn through and it'll break right away. That's why every thermostat also has an adapter to connect to the boiler.
Step 2: turn off the AC power
Turn off the power of the boiler or turn off the AC power in your fuse box, to be sure. You'll work with high voltages, so make sure there's really no power on the cables. Make sure the boiler is really turned off. Do this before you turn on the heating. If the temperature doesn't rise, your boiler is turned off.
Step 3: connect your adapter
Connect the adapter of your thermostat to your boiler first. Do this according to the schematic that came with your thermostat. Next, connect the adapter to the power grid. You'll have 2 wires for this. You'll have a brown wire to connect to the Live or L connector. Connect the blue wire to the N or Null connector. Don't you have these wires yet? Strip an old cable first and connect the 2 wires to your adapter.
Step 4: connect your thermostat
Connect the 2 wires of your adapter to the thermostat. Connect these to the 2 right ports of your adapter and to the ports with the same letters on your thermostat. You can find the cables of the boiler behind your old thermostat. Connect all cables of your previous thermostat to your new thermostat according to the instructions in the manual.
Step 5: install the thermostat
Turn the power grid back on and install the thermostat according to the manual. The thermostat will turn on automatically. Set up the thermostat via the display of the thermostat and via your smartphone app.
