Thanks for the quick response, restarting the timer should clear any common fault.
The engineer manual can be found here, you could try placing it in the engineer mode by holding down the top 3 buttons (PROG, + and DAY) under the cover for 5 seconds, press the next button to cycle through the settings and it should go back to user mode.
The good news is this shouldnt be a boiler fault, the controller is just a relay which tells the boiler when to start, and would be unlikely to cause this issue, so the focus should be around the controller itself.
If placing it in engineer mode didnt work, the next step would be to check the dil switches on the back of the panel encase they have somehow changed, see section 3.2 of the attached manual. If SW1 and SW2 are both as per the manual diagram this is correct, and would suggest a hardware failure in the controller itself, as you will see by the manual its not a big job to change the controller, the important thing is to switch off the mains power before going need the cables.
Please let me know if you manage to get the unit working or need further guidance on replacing the controller.