Hi .so , just to clarify. The timer clock does not work , and your heating and hot water dosnt work either?
Was he a professional electrician?
To be honest its a tricky situation because you need your hot water and heating asap. If you bought it locally , you could return it , get the replacement . the chances of another one being a lemon would be zero and would confirm it was a faulty clock. But if money was no issue get another electrician or preferably a boiler and heating engineer to check it, because electricians don't really understand heating controls and how they are wired .