Drayton digistat rf3 problems?

I have a drayton digistat rf3. Battery symbol came on and i replaced battery according to the instructions. The scr flashes for 2 sceonds as per the instructions and red & green lights stay on, but it doesn't look like the wireless part is connecting to the scr. I have tried resetting both boiler & wirless part, taken out batteries etc but nothing! The PDF suggests that if the SCR needs changing the red light will continuously flash. The boiler works for hot water, but not heating. Has anyone got any advice? Do i need to change SCR / wireless thermostat or is there something else i can do / reset it? Thanks