A valve assembly controlling fuel flow to a combustion appliance, the combustion appliance cycling on and off during a sequence of operational cycles, at least some of the operational cycles of the combustion appliance each performing a valve proving test prior to and/or after igniting the fuel during the operational cycle, the valve assembly comprising: a valve body having an inlet port and an outlet port, with a fluid path extending between the inlet port and the outlet port; a first valve (20a, 22a, 30a),situated in the fluid path between the inlet port and the outlet port; a second valve (20b, 22b, 30b) situated in the fluid path between the inlet port and the outlet port downstream of the first valve, with an intermediate volume between the first valve and the second valve defined by the valve body; a first valve actuator, secured relative to the valve body, for selectively moving the first valve between a closed position, which closes the fluid path between the inlet port and the outlet port, and an open position; a second valve actuator, secured relative to the valve body, for selectively moving the second valve between a closed position, which closes the fluid path between the inlet port and the outlet port, and an open position; a pressure sensor in fluid communication with the intermediate volume between the first valve and the second valve for sensing a measure that is related to a pressure in the intermediate volume; and a controller secured relative to the valve body and in communication with the pressure sensor, the controller configured to determine a measure that is related to a pressure change rate in the intermediate volume during each valve proving test that is performed as part of at least some of the operational cycles of the combustion appliance; characterised in that: an inlet pressure sensor positioned upstream of the first valve for sensing a measure related to the pressure upstream of the first valve; an outlet pressure sensor positioned downstream of the second valve for sensing a measure related to the pressure downstream of the second valve; the controller is coupled to the inlet pressure sensor and receives the measure related to the pressure upstream of the first valve; and the controller is coupled to the outlet pressure sensor and receives the measure related to the pressure downstream of the second valve. a valve body having an inlet port and an outlet port, with a fluid path extending between the inlet port and the outlet port; a first valve (20a, 22a, 30a),situated in the fluid path between the inlet port and the outlet port; a second valve (20b, 22b, 30b) situated in the fluid path between the inlet port and the outlet port downstream of the first valve, with an intermediate volume between the first valve and the second valve defined by the valve body; a first valve actuator, secured relative to the valve body, for selectively moving the first valve between a closed position, which closes the fluid path between the inlet port and the outlet port, and an open position; a second valve actuator, secured relative to the valve body, for selectively moving the second valve between a closed position, which closes the fluid path between the inlet port and the outlet port, and an open position; a pressure sensor in fluid communication with the intermediate volume between the first valve and the second valve for sensing a measure that is related to a pressure in the intermediate volume; and a controller secured relative to the valve body and in communication with the pressure sensor, the controller configured to determine a measure that is related to a pressure change rate in the intermediate volume during each valve proving test that is performed as part of at least some of the operational cycles of the combustion appliance; characterised in that: an inlet pressure sensor positioned upstream of the first valve for sensing a measure related to the pressure upstream of the first valve; an outlet pressure sensor positioned downstream of the second valve for sensing a measure related to the pressure downstream of the second valve; the controller is coupled to the inlet pressure sensor and receives the measure related to the pressure upstream of the first valve; and the controller is coupled to the outlet pressure sensor and receives the measure related to the pressure downstream of the second valve. an inlet pressure sensor positioned upstream of the first valve for sensing a measure related to the pressure upstream of the first valve; an outlet pressure sensor positioned downstream of the second valve for sensing a measure related to the pressure downstream of the second valve; the controller is coupled to the inlet pressure sensor and receives the measure related to the pressure upstream of the first valve; and the controller is coupled to the outlet pressure sensor and receives the measure related to the pressure downstream of the second valve.