A valve comprising a controller, a fluid path, a valve member situated in the fluid path; the valve member being selectively movable between a closed position which closes the fluid path and an open position which opens the fluid path; the valve comprising a valve actuator coupled to the valve member; the valve comprising a heater, a first (5; 5a; 5b) and a second (5; 5b; 5a) temperature transducer; the controller being in operative communication with the valve actuator, with the heater and with the temperature transducers (5; 5a, 5b) and being configured to: send a close signal to the valve actuator, the close signal causing the valve actuator to close the valve member thereby closing the fluid path; record a first temperature signal from the first temperature transducer (5; 5a; 5b); produce a first temperature set point; control the heater to attain the first temperature set point at the second temperature transducer (5; 5b; 5a); characterised in that the controller is also configured to: record a first quantity associated with controlling the heater to attain the first temperature set point, the first quantity being indicative of: - an amount of time required to attain the first temperature set point; or - an amount of energy required to attain the first temperature set point; and send an open signal to the valve actuator, the open signal causing the valve actuator to open the valve member thereby opening the fluid path; record a second temperature signal from the first temperature transducer (5; 5a; 5b); produce a second temperature set point; control the heater to attain the second temperature set point at the second temperature transducer (5; 5b; 5a); record a second quantity associated with controlling the heater to attain the second temperature set point, the second quantity being indicative of: - an amount of time required to attain the second temperature set point; or - an amount of energy required to attain the second temperature set point; and employ the first quantity to classify a fluid inside and the second quantity to estimate a flow rate of the fluid through the fluid path. send a close signal to the valve actuator, the close signal causing the valve actuator to close the valve member thereby closing the fluid path; record a first temperature signal from the first temperature transducer (5; 5a; 5b); produce a first temperature set point; control the heater to attain the first temperature set point at the second temperature transducer (5; 5b; 5a); characterised in that the controller is also configured to: record a first quantity associated with controlling the heater to attain the first temperature set point, the first quantity being indicative of: - an amount of time required to attain the first temperature set point; or - an amount of energy required to attain the first temperature set point; and send an open signal to the valve actuator, the open signal causing the valve actuator to open the valve member thereby opening the fluid path; record a second temperature signal from the first temperature transducer (5; 5a; 5b); produce a second temperature set point; control the heater to attain the second temperature set point at the second temperature transducer (5; 5b; 5a); record a second quantity associated with controlling the heater to attain the second temperature set point, the second quantity being indicative of: - an amount of time required to attain the second temperature set point; or - an amount of energy required to attain the second temperature set point; and employ the first quantity to classify a fluid inside and the second quantity to estimate a flow rate of the fluid through the fluid path. record a first quantity associated with controlling the heater to attain the first temperature set point, the first quantity being indicative of: - an amount of time required to attain the first temperature set point; or - an amount of energy required to attain the first temperature set point; and - an amount of time required to attain the first temperature set point; or - an amount of energy required to attain the first temperature set point; and send an open signal to the valve actuator, the open signal causing the valve actuator to open the valve member thereby opening the fluid path; record a second temperature signal from the first temperature transducer (5; 5a; 5b); produce a second temperature set point; control the heater to attain the second temperature set point at the second temperature transducer (5; 5b; 5a); record a second quantity associated with controlling the heater to attain the second temperature set point, the second quantity being indicative of: - an amount of time required to attain the second temperature set point; or - an amount of energy required to attain the second temperature set point; and - an amount of time required to attain the second temperature set point; or - an amount of energy required to attain the second temperature set point; and employ the first quantity to classify a fluid inside and the second quantity to estimate a flow rate of the fluid through the fluid path.