Try to switch off your Vitotwin for a while
alizadeh, before you do anything drastic such as switching off the Vitotwin (which should anyway never be done while the Stirling is running!), you should check if the remote control works at all, e.g. if it shows electric power ("Leistung") or any temperatures when repeatedly pushing the "i" button.
If the remote does not work, first thing is indeed to
check the batteries in your remote control
In order to do that you probably have to remove the batteries. If I were you I would change them in any case. After that, you have to re-initiate the radio connection according to the manual "Funk-Fernbedienung" (page 7/8, resp. 9/10 if you have a radio repeater installed). It's less complicated than it looks - if you don't have German enough to understand the instructions in the manual, maybe a friend can help you.
The manual describes also a testing procedure for the quality of the connection (page 9 resp. 11). I have never tried that, but it may show you if you have a poor connection.
If the remote DOES work but the default 85 remains, the Vitotwin manual recommends a restart (for the remote, not for the Vitotwin): On your remote control, switch to the "Funk" menu, scroll to Code 140 "Alle Geräte löschen", scroll to "ja" and push "OK". This cuts off the (probably faulty) radio connection between Vitotwin and remote. After that you have to re-initiate the connection as described above.
If these measures don't work, you should directly call the company that has installed your Vitotwin. There may be a faulty contact or wire connection between the Vitotwin and the sender, or maybe it's the sender itself, but you can't check that yourself.
If you have any questions about this or any other fault, please don't hesitate to contact the Forum again.
Good luck,
Sailor