A valve for an adsorption heat pump may be adjustable between a closed position, a first open position, a second open position, and at least one intermediate position. The valve may include a first channel, a second channel, a third channel, a first valve unit, a second valve unit, and a spring element providing a closing force upon the first valve body and the second valve body. The valve may also include an actuating drive configured to hold the valve in position without power. The actuating drive may include a stepping motor and a gear unit constructed and arranged to hold the valve in position via a currentless holding moment. The first valve unit and the second valve unit may have a valve opening characteristic of a flow coefficient dependent on an adjustment path that is not linear. The valve opening characteristic may include at least one flat region.