Like most people in the UK, the boiler's in the garage. A brick rectangle separate from the house. Did Vaillant include an ethernet port? You bet they didn't. The support team suggested I installed WiFi in my garage, which definitely wasn't going to happen.
I had to get the installer back and he ran the cable through the wall so it's now inside and working fine - but how did this ever make it to market? No wonder the reviews are all terrible.