Combi boiler can't restart after turning off for hols?

Worcester Si24-28 Combi boiler.
Turned off at fascia panel for hols, turned back on and now no hot water or heating. Have done this before without any problem and it was working fine before this time.
Manual says to turn seperate room temperature regulator dial to full along with the heating dial on the boiler to full then turn on at boiler to reignite but nothing happening.
Any pointers appreciated.