A man in his 20s was left with a broken jaw when robbers attacked him with a mallet.
Lincolnshire Police is investigating the burglary reported to have happened between 2.30pm and 3pm on Sunday, July 28.
The offenders made off with cash after the burglary at an address on Adelaide Close in Waddington.
Investigators are looking into whether the burglars, who were both described as white with an English accent, were using a vehicle.
They were both described as aged between 35 and 40. One was reported to be over six feet tall with a broad build while wearing all black.
The other man was around 5 feet 6 with black hair, a black goatee and was wearing a grey tracksuit.
Anyone who was in the area at the time or recognises the description of the men is being urged to call 101 and quote incident 19000405330.