Invested in a new Baxi 170L Main Direct and the off peak immersion overheated within a week and the on-peak shortly after, leading to me calling the plumber back in and then an electrician to troubleshoot at extra expense. After ruling out other issues and reporting it to Baxi, the thermostats were both replaced and configured differently to minimise overheating issues. With my previous old system the immersions lasted several years. Baxi are not taking responsibility for the inconvenience caused by their setup on a brand new product and consider a warranty fix to be sufficient. Their customer service is mostly good but I have low confidence in their products given the immediacy of issues. Use them at your own risk!