Hi all, just a quick update.
When investigating closer I found the contacts on the starter contactor had welded together so the pump was never turning off by the timeclock.
I thought using 240v from the timeclock just wouldn't switch the contactor, however being as the customer said it used to work I'm thinking now that 240v was operating the contactor and caused it eventually to weld closed due to arcing.
I fitted new starter with 240v coil and all now seems to be working correctly.
Thank you again for all advice given..