Hello! I'm rennovating a house that I intend to rent out. Essentially
I have two bathrooms, each of which is going to have a bath with
shower over. I want to be able to run both showers at once (as there
will be six people in the house), and my plumber thinks the only way
to do this is with electric showers. Does anyone know if there's a way
to run two showers (with thermostatic mixer valves) at the same time
off the one combi boiler I'll be putting in, or is my plumber right?

Thanks for your help,
Ellen