type 44 heater valve

[Nick Lawrence]

I have '90 100, 90 200, 91 100.
Asking about the water heater valve. 
     the '91 100 has an electrical connection
     the '90 100 has the wirng but has not had a valve with electric since I've owned it (several years)
     the  '90 200  no electrical connection on valve, don't remember seeing any wiring.

So I ask, what is it for?  Does it need the connection?   
The non_electrical are a little shorter and it is a stretch to fit hoses.
Local flaps don't show a heater valve with an eclectrical connection in  the listings.

TIA
Nick  central Ohio