Control system for one or more ablutionary devices

A method performed by the control system of an ablutionary device, the control system comprising a mixer valve having a first inlet and a second inlet configured to receive a supply of hot and cold water, and an outlet configured to output cold water, hot water, or a mixture thereof as an output stream for supplying water to the one or more ablutionary devices downstream of the mixer valve, wherein the mixer valve comprises first and second valve members forming first and second flow control valves arranged to control flow between the inlets and the outlet, the method comprising:

• controlling the mixer valve during use according to one or more target output water properties of the output stream, the one or more target output water properties being set by the user of the one or more ablutionary devices, by controlling the position of the valve members in order to control the output stream;
• obtaining two or more current operating signals related to the flow rate of the output stream produced by the mixer valve, the one or more operating signals including a current target or current actual position of both of the valve members;
• comparing each of the two or more current operating signals to a corresponding historical operating signal, the historical operating signal being a previously obtained operating signal, the corresponding historical operating signal being a corresponding historical target or actual position of both of the valve members;
• and
• generating a diagnostic signal based on the two or more comparisons;
• wherein after the diagnostic signal is generated, the controller:
• transmits the diagnostic signal to at least one of a user interface and a remote device, and
• adjusts the flow rate of the output stream based on the generated diagnostic signal.