I have a Worcester Bosch 28Si11. Only a few years old and it cuts out every 4 or 5 days. So far two gas engineers have not been able to solve the problem as the boiler was behaving itself when they came round. Worcester Bosch don't reply to letters and emails, expecting to be phoned on premium rate numbers ( which I won't do, having already spent a lot of money with them ). Any suggestions as to why this problem comes about and what can be done to fix it. Would appreciate any replies... Thanks