I have four zones (four thermostats) running from a single boiler. I
need to remove two of the zones completely (remove all of the piping).


Should I join the "supply" and "return" for each zone, or should I cap
off "supply" and "return" separately for each zone (each loop)?

Do I need to turn off the water supply to the house to do this???

(PS: this needs to be done because an electrician is installing
baseboard heat in the those two zones)...

Thanks...