heating system?

I had a glow worm 24hxi boiler fitted to my existing y plan system using the original controls(programmer,room and cylinder stats etc)The boiler works fine when central heating is selected but when hot water or ch and hw are selected the boiler temperature rises quite quickly and the boiler shuts off until the temperature drops and then it tries again but again shuts down until the temperature drops and so on.The only way to get it to heat the cylinder is to increase the temperature setting on the boiler from the 54 used for c. h. to around 65+ .The cylinder is situated above the boiler about a metre away and the boiler is on the basic control panel with no options board fitted.Would the fitting of an option board cure this problem by selecting different temperatures for ch and hw.The system was thoroughly flushed through before new boiler fitted.