"Ellen Rawlinson" wrote in message
om...
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?

There are a lot of issues here regarding adequacy of electric supply (for 2
electric showers), adequacy of cold water pressure, adequacy of gas supply
at boiler for large combi or (whispering) 2 combis.

But to respond to your specific question it may be helpful to look at
electrical shower outputs. These are commonly 8.5kW, 9.5kW or 10.5kW. A
combi is 24kW, 28kW or 35kW electrical equivalent. So in heating terms a
combi produces more hot water than 2 electric showers. If there is good
mains pressure it should be easy to equitably share the flow by plumbing the
showers in small enough bore. IME the Screwfix bar mixer works well across
a range of pressures. Of course you have got to stop the other bath
grabbing too much water as well. Its really a design problem which is
probably why the plumber is struggling. He may also know a friendly
electrician because for 2 electric showers you will definately need a good
one. If there is poor cold pressure you are stuffed either way.

Anyway its rented accomodation, has to be safe but who says it has to be
good? Or have matters improved since I was in rented accom....

Jim A