Officers were called to a house in Ersham Road in the early hours of Saturday morning (7 October).
Four people had broken in and demanded money from the occupant. The victim, a man in his 80s, was threatened and forced to hand over cash. He was hit on the head and treated in hospital.
Following in extensive search of the area, no suspects have yet been identified.
Anyone who saw what happened or may have doorbell, CCTV, or dash cam footage from the area are asked to get in touch. Information can be reported online or by calling 101 quoting serial 37 of 07/10.