Mt home heating is NOBO which is run by an app on my iPhone. Where I am on wifi I can connect to and operate the heating remotely. If there is no wifi and I have to rely on Mobile 3G or 4G it won't connect and I get a Network Connection error message on the app. When I was on TalkTalk (don't worry I on't regret the move) it did work but not since I've been on PlusNet. The Guys at PlusNet wondered if Port Forwarding might hlelp but that seems a minefield for the amateur. Any ideas?