Ideal pump over run and cold tap in bathroom problem?

Hi, we recently had a new ideal boiler fitter and so getting to know the system - we had to let air out of the radiators and then saw that we had a message on the boiler which says pump over run - the system seems fine and working but now the cold tap in the bathroom is not working properly as you have to turn it five times and then the water shoots out rather than just turning the tap on and getting a normal flow - any clues as to what it could be - we have had the tap off and all seems fine - grateful for any comments.