Join Date: Sep 2013
Location: South Devon
My Motorhome: Bessacarr E725
Thanked 161 Times in 140 Posts
Inline pumps as used on pressurised systems are diaphragm pumps which are 'positive displacement pumps', which means that each action of the pump shifts a certain amount of water. It's a smoothish pulsing action, further smoothed if you have an accumulator fitted as well.
A submersible pump is usually a centrifugal type, with vanes spinning in the open base that grab the water and compress it into the pipe. This type of pump can run for some time without the water actually flowing, as the water surrounding it keeps it cool. As long as it isn't forgotten, I'd have thought that the main shower tap could be opened to activate the pump and set the temperature, and then the flow controlled by the trigger head.
Simplest set-up, which I have, is a lifting mixer tap which does it all.
I'm daft and proud of it.
Last edited by tugboat; 07-11-2016 at 07:29.