thermostatic power switch controlled from temperature of hot water pipe

[tayloa17]

hiya,

Is there such a thing as a thermostatic power switch controlled from the temperature of water inside a pipe? If so what is this called, and who if any produces this?

Context is i'm exploring the idea of a hot water supply system which consists of two parts:

1. main supply: unvented hot water cylinder
2. back-up supply: instantaneous electric heater

For this to work, the two systems would operate in series, with the "hot" output from the main supply feeding the cold input of the backup supply. For safety, the latter backup supply would be controlled with a switch (fail-safe OFF) which would be activated (ON) only if the input temperature drops below (say) 20 degrees, ie if the main supply has run out or is switched off.

Any info or suggestions welcome.

Thanks!

 

[snowhead]

Pipe thermostat.

No comment on the idea tho.

 

[Mike Jackson]

So you want to get a unit that has a flow rate in excess of 30 l/min and throttle it down through an instantaneous electric water heater to 5 or 6 litres a minute. Great idea you should patent it.

 

[tayloa17]

I love the internet, only a couple of minutes to scope out mad-cap ideas

Thanks for your feedback so far.