Wickes Shower Pump not starting up

I have a Wickes Twin Impeller 2 Bar shower pump (Product 160510) that is just over 3 yrs old. This week it has stoped turning on when the shower is turned in. However if I give the pump enclosure a tap on the side it fires up.

What can I do to get this problem fixed? I wonder if its a limsecale issue, but havn't got to the point of seeing whetehr I can take it apart and clean it.

Thanks

if a technicians tap works it could be a loose connection,these things are not servicable,you may need to replace it.
http://www.screwfix.com/prods/70280...r-Shower-Pump-2-0bar-Pump-with-Isolators-CT75

After some research I found a someone with a very similar problem and their pump humms when the shower is turned on and mine does as well. Their resolution was to replace the start capacitor and the guideance was that it is a 'big white cylindrical item' next to the PCB.

So I opened up the casing to expose the PCB, but I cant see anything that looks like the described capacitor.

Can anyone help me with this?