1. A method for determining a condition indicator of a water analysis apparatus, the method comprising: providing a water analysis apparatus configured to measure at least two different technical parameters; determining a respective parameter value for each of the at least two different technical parameters of the water analysis apparatus using at least one of a sensor and a counter; determining a respective deviation value of each of the parameter values with respect to an associated respective parameter reference value for each of the technical parameters; determining a respective deviation relevance value from each of the deviation values using a respective parameter-specific deviation relevance function for each of the parameter values, the parameter-specific deviation relevance functions being different from each other; calculating, using an indicator function, a condition indicator from the determined deviation relevance values; and determining an overall condition of the water analysis apparatus using the condition indicator.