Two of the intruders had knives and a third a golf club, police said.
The masked men then forced the occupants of the house to go to the Smithdown Road post office and withdraw money from the machine.
The masked men then left on foot.
One of the intruders had short dark brown hair, was of medium build, and was about 6 feet tall.
He was dressed in black with a black cap, a black long-sleeved top and black pants.
The second intruder was about 5 feet 7 inches tall and was thin. He was wearing a thin North Face puffer jacket, a balaclava, a black cap and black pants.
The third was about 5 feet 6 inches tall, stocky, and had a shaved head. He was wearing black sweatpants and a black hooded top with the hood over his head.
Detective Inspector Simon Hurst told ECHO: “It was a shocking incident. Fortunately, no one was injured but the occupants of the house were shaken by their ordeal.
“I appeal to anyone in the area of Gresford Avenue or Smithdown Road, especially taxi drivers or motorists, who have seen something suspicious or who may have captured something on camera panel to contact us as they may have vital information for our investigation. ”
Anyone with information is requested to DM @MerPolCC or @CrimestoppersUK anonymously on 0800 555 111 citing reference 20000454686.