Hello! My partner bought a BOT 313Wifi thermostat for our volkera boiler (Installed 2016) assuming I'd have no trouble wiring it up! Trouble is, I'm not certain and don't want to cause any short circuiting! Our existing thermostat is bluetooth via the wire below. Can anyone advise on which wire goes where??! My boiler wire, thermostat and the diagram are attached. Thank you!!!!