steam boiler wiring

I have a weil mclain steam boiler. PEG-30A-S-PI, nat gas, single pipe/zone. Trying to wire up a wifi tstat with a C wire.

Old tstat had w from transformer wired to w and y from transformer wired to R/Rc per this schematic. https://goo.gl/photos/VLr1UA58Escsjgcy7

Just ran 18/5 wire and trying to figure out how to wire up new t stat to the transformer properly with a C wire. Should I also connect up R from the transformer? Any help is much appreciated!

Edit: I should have put this in Controls. I cant figure out how to delete it. Sorry..