Marietta Comeau

My Worcester 2000 boiler is displaying a low pressure error message. Sometimes the hot water runs out (this was also happening also before the low pressure issue). I had an electrician come and check the electricity and he said all is good. The next day the hot water still wont work and he says i need to contact a "plumber". The light appears to be on and the water tank is full however, there is no hot water. There's an instant hot water shower that id not working. In the event you loved this...