Charity, Crimestoppers, says a weapon was used, believed to have been a handgun, to strike a woman who was in the property.
It happened in Sevenoaks on the afternoon of Friday the 21st of June.
At least 50 high-value pieces of jewellery and watches worth £1.8 million were reportedly stolen.
Detectives believe this person has struck across south-east England for 18 years including several times in Surrey since 2006.
A woman suffered a broken jaw when a man attacked her while robbing her home in Kingswood in October 2017.