zanussi w1042w erratic behaviour

Hi, I usually only use 2 programmes, mainly ‘fast colours’ and ‘whites’. When using ‘fast colours’ the machine will not do its final spin – it tries to for about a second and stops. Sometimes it stops pumping before the drum is empty but will do so if I put it on drain only. I first checked the filter, this was clean. I have also checked the pressure switch, this is working correctly and is not blocked. In ‘Whites’ mode it sometimes appears to have done a fast spin as the laundry is fairly dry and sometimes doesn’t. Also in this mode it sometimes seems to have got to the end of its cycle faster than in ‘fast colours’ mode. Sometimes the laundry is still hot from the wash and sometimes not, as if the water has not heated to the correct temperature. Generally it doesn’t appear to fill as high as I would expect it to but then I don’t know if the water level should be visible through the door. I feel like scrapping it but am loath to as it has not had much use (average 8 washes a month for last 6 years and hardly at all before then) Please help!!!