Well if the heat link clicks you must have power to 11, So there should also be power to the heat links 2 common connections (2+5). Points to check:
Is the hot water cylinder already up to temperature?
Has terminals 2 and 3 in the wiring centre been linked together?
Are the links set as per the instructions in the wiring centre lid?(for biflo)
If all the above has been done, do you have a multimeter? Can you post photos of the wiring centre and heatlink wiring, might be able to spot a wiring error quickly.
Cylinder is cold haven't had HW on today, links between 2 and 3 are in place.
I will try dig my multimeter out of the shed.
Checked all the wiring links as per the lid and there correct, there also extra links that were there prior to start these are from 3 to 12, 6 to 12, 9 to 3, 10 to 15 and 12 to 13 are any of these to be removed?
Thanks for all your assistance so far it is much appreciated!