Abstract: An integrated heater assembly (190) is operable to provide a supply of solution from a tank (200). The assembly (190) includes a head arrangement (290) for mounting onto a hole of the tank (200), and a heating element (210) for selectively warming the solution in the tank (200), wherein the heating element (210) includes a duct through which fluid for heating the solution is operable to flow, and wherein the head arrangement (290) includes a valve (220) for controlling flow of the fluid within the duct. The valve (220) is optionally retained in a snap-fit manner within a plastics material moulding of the head arrangement (290). Moreover, the valve (220) is optionally an electromagnetic solenoid valve. The assembly (109) is beneficially adapted for coping with urea solution in the tank (200).