the machine seems to be ok apart from it leaving about 1ltr of water in the filter at the bottom right corner, this starts to smell if not manually drained out. the machine is a BWM 129. any suggestions?
This is a normal amount of water left in the sump of a washing machine. If the machine is not used for a day or two then the water will go stagnent and start to smell, especially if it's a warm day. Low temp washes encourage this as bacteria can survive in washes that do not exceed 60 c. A rinse would be better than emptying filter too often as the seals will wear and will leak from filter.