How can i fix my Halstead Eden CBX 32 combi boiler?

Halstead Eden CBX 32 Combi Boiler , No Running constant hot water fault......All the orange fault lights stay on most of the time. Then we have to constantly reset the boiler light so it is staying blue. The boiler will not give us constant hot water to the lower part of the house, it runs cool or cold after a few seconds and the central heating is not over hot to the radiators.The system is about 3 years old. We had it installed by a professonal plumber.it has never really be effiecent.can any one help.