Heating Engineers please help!?

I had problems with my boiler (Myson Apollo 5Si) in that it was not working at all. I have had a new circuit board fitted but now the timer switches for the heating and hot water are not working. So I can have plenty of heat and hot water, just not timed. To switch it off I am having to switch off the main switch by the boiler itself. My engineer is coming back tomorrow. I just wanted to check whether it is the circuit board which controls the timer switches (to determine whether they should treat this as the same job). This problem had never occurred before the new circuit board was fitted. Any advice greatly received.
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Heating Engineers St Albans|Heating Engineers Welynn Garden City