We have Brivis ducted gas heating. Not sure of the model number, but it was installed in Feb 2007 and the Owner's Manual is dated June 2006. We have had a few error codes on the networker over the years, and have been grateful for tips on forums like this. One day before the shortest day of the year, we awoke to a freezing Canberra morning and turned on our heater manually. The networker froze, and we seemed to have error code 59#, which is not mentioned in the Owner's Manual.
After we pushed a lot of buttons on the networker, including various combinations and long presses, inspired by a post in this forum on a related but different problem, we gently took the networker off the wall, to disconnect it from its power supply. We replaced it about 2 minutes later, but it didn't fix the problem. Took it off the wall again (by gently twisting it upwards from the bottom), and left it disconnected for over 5 minutes. When it reconnected, the error code was gone, the networker was unfrozen, and heating resumed.
Love the nature of this forum, and wanted to give something back in case someone is ever looking for a potential fix for error code 59.