Welcome! Here are the website rules, as well as some tips for using this forum.
If you've found help here, check back in to let us know how everything worked out.
It's a great way to thank those who helped you.
I'm getting ready to replace my old boiler. New boiler is most likely going to be a Vitodens 200. My existing primary secondary loops are 1" while the supply and return on the new boiler are 3/4". Any issues with keeping the existing piping and just reducing to 3/4 at the boiler?