I have an old house (~130 years) that has a hydronic baseboard system installed. The heating system is improperly plumbed: the 1st floor thermostat controls half the heating on the first floor and half the heating on the second. The second floor thermostat controls the other half of both floors.
I'd like to fix it.
The current system seems to use diverter-tees. More importantly, not all of the piping running to the baseboards are the same size. I didn't measure exactly, but I think most of it is 3/4", and some is 1/2".
Can I simply cut out the existing system and connect all the baseboards together in series? Will the different pipe sizes cause significant issue?
My rough plan is to split the floors into two loops each, so that I don't end up with cold water at one end up of the loop.