Aspects of the present invention relate to an apparatus comprising at least two chambers, each chamber comprising at least one wall defining the chamber, a fluid inlet and a fluid outlet through the wall of the chamber and an opening separate from the fluid inlet and fluid outlet. The fluid inlet and fluid outlet are configured such that a fluid enters the chamber via the fluid inlet and exits via the fluid outlet. A gas enters the chamber via the fluid inlet and exits the chamber via the opening, wherein the opening of each of the chambers is fluidly connected to a common fluid reservoir. The apparatus may be used for degassing multiple coolant circuits in a vehicle.