I have a vokera compact boiler been paying a maintenance plan for it . Had an engineer out 15 or more times last winter boiler keeps going to red.. Starts up fine evrytime I turn it back on . Problem is still the same with boiler engineers can`t work out what is wrong with it. It had a blocked flexi pipe going into the boiler engineer crimped pipe with pliers and blocked the whole system they had to replace the pump twice and numerous other parts that he had damaged..but original problem is still there it can stay on sometines for a couple of hours other times cuts out 10 mins after turning it on..Problem is the same whether it is turned to water only or radiators and water. Any advice would be much appreciated[wiki][/wiki]