My VW unit is a magnet type valve - mono-stable. It draws about 250mA when activated. It is normally open so the coolant gets a chance to move through the heater core once in a while. When power is applied the valve closes. As soon as you remove power a return spring forces the valve open. I like it. Got a brand new unit for about $20. The only thing I'm not too happy about is how loud this darn thing is It closes with a noticeable "clunk" but I can live with it... with the engine running it's not really an issue. I'm sure it will be better once I get new carpeting installed. Those bare floors resonate a lot.
I'm sure your motor driven one is a lot quieter than this.