Problems installing extension

Hi there, new to Tado.

Installed the thermostat today, seemed to be working great, my kit also came with an extension which I assumed was for the water, started installing that, only for the instructions to say this was a complicated installed and I needed to email Tado, which I have done.

However, now my heating isn’t working as the app says the extension kit isn’t working and I have no option to remove the device.

And advice as it’s cold today and Tado aren’t going to respond until tomorrow at the earliest