Yes you do have the recirculating heater. The factory way of shutting off the flow is a valve like this at the thermostat housing.
http://www.flickr.com/photos/advance-design_parts_co/8377101217/in/set-72157631868452754
For my own heater I constructed a set of custom SS valves.
http://www.flickr.com/photos/advance-design_parts_co/8129060091/in/set-72157631867396207