I am not sure if it is the same problem as I had. But try puttiing your hand on the pump to see if it is getting hot. Also another tip is to put a screw driver tip on the casing of the pump and your ear to the handle this is an easy way to check if the motor is still running but the pump is not.
Hope it is of some help to you. I'm sure the professionals will be on later to give you the right advice.
If the noise was coming from the bottom of the boiler it could be the P.C.B. try giving it a tap underneath (back right hand corner) if it fires up you will need a new P.C.B.
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local