I have an MS 270 and the manual says that it has a 'shutter' to allow it to heat up faster in the winter. Supposed to be able to toggle it with a screwdriver. I even see the little sun and snowflake symbols. The ads for the MS270 also say that it has a preheater shutter.
Only I don't have one. I had one on my older 026, but there's nothing there on this one. I took the cover off and there's a clip there, but nothing liuke a toggle with any kind of 'shutter'. A dealer showed me the IPB, and neither he nor I saw anything.