Hiya every time I get in my shower you can guarantee someone will flush the toilet or turn the tap on at the kitchen sink and due to low pressure the shower runs cold . I was thinking if I connect a tail to the normally closed solenoid valve inside the shower box and run it to a normally open solenoid valve in the toilet supply and then one to the sink that would sort it out nice hot shower . Ie when the shower is switched on no one can run the water win win ??. Any feedback would be welcome thanks Keith .