Smart Boiler Device will not pair WIFI 2.4 ?!?

There are some real experts around here in IoT gadgets. Another strategy is to search here for the brand of the device you want to connect.

Until they step in here's some random advice. In your case, SemiCom is a new one on the community.

Most IoT things work on 2.4 GHz. They will not see, and cannot connect to, 5 GHz wifi.

Many makers of IoT devices use an app on a mobile device to set up the thing. Mobile devices usually connect to 5 GHz wifi and may not let you choose 2.4 GHz. The setup app should be able to connect to 5 GHz wifi and still talk to things on 2.4 GHz.

Poorly designed apps fall over because they cannot handle installation using a mobile connected to 5 GHz wifi while the IoT device is on 2.4 GHz.

A widely used strategy that works for many people is to forget about separate SSIDs and to follow this strategy:

1. Go into your router's wifi set up (see below)
2. Disable broadcast of 5 GHz SSID
3. Tell the mobile device to forget the connection to that SSID
4. Reboot the mobile device
5. Connect to the SSID
6. Set up the IoT device
7. Go back and reverse step 2

You may be able to miss out steps 3 and 4, depending on your phone and the app.

This approach has worked for many people.

To work out how to turn of the 5 GHz wifi, visit the support pages:

Support | NETGEAR

Feed in your router's model number and check the section in the manual Enable or Disable the WiFi Radios. The exact working may differ for your router.

You could also ask the people who made the SemiCom device how you should work with a Mesh network. Or wait for a real IoT expert to arrive here.