My Trianco centrajet 13/17 wall mounted oil boiler,which is long overdue for replacement,has been working fine until today.After starting up this morning it ran for about half an hour and then started to make an almighty noise before failing,and will not start again.The noise seems to be coming from the area of the motor or oil pump and sounded like a bearing failure.I'am probabley totally wrong with my diagnosis so would appreciate any help from you guys out there.