Understanding lifetimes and failure modes of defective washing machines and dishwashers.

The available literature on average lifetimes and failure modes of household appliances is mainly based on results of surveys conducted among end-users, but very little precise information can be found on specific failure modes and repair rates. The main objective of this study is to provide quantitative data about frequent failures and average service lifetimes of two household appliances, through the analysis of repair services performed by professional repair operators. We based our analysis on available datasets provided by a representative independent repair centre based in Europe, and we focused on the failures most frequently occurring and the potential repair or discard of the appliances. A database of about 11,000 diagnoses on defective washing machines and dishwashers was analysed, and frequent failure modes and repair rates were identified. The analysis was supported by a tailored visualisation of results. Concerning washing machines, recurring failures diagnosed by the repair operator regarded the electronics, shock absorbers and bearings, doors, carbon brushes and pumps. While the highest repair rates (repaired devices over total diagnosed devices with a specific failure mode) were observed for doors, carbon brushes and removal of foreign objects, the lowest rates were observed for bearings, drums and tubs, circulation pumps and electronics. Regarding dishwashers, recurring failures involved pumps, electronics, aquastop and valves, foreign objects and doors. The lowest repair rates, however, were again observed for circulation pumps and electronics. We also observed that the average service lifetime of an appliance not repaired by repair centre operators is 12.6 years for washing machines and 12 years for dishwashers. This work brings important knowledge on lifetimes and failure modes of defective washing machines and dishwashers, concerning in particular weak and critical components, but also age of appliances to be repaired. Based on the exercise on the two appliances, we discuss a possible classification scheme for repair services of household appliances, including both information retrieved by professional repair operators and information retrieved through interviews with end-users.