A victim was held on their sofa while a pair of robbers held them down and two others searched the property and then stole cash on Monday.
Police are appealing for witnesses after the four men entered the address in Breadcroft Lane at around 6.30pm.
The incident is believed to be linked to a theft at another property in the street on the same day where cash was stolen after thieves forced open the front door.
Det Con Kieran Doyle, who is investigating, said: “I would like to stress that incidents of this nature are very rare.
“Although he was not hurt, the victim has been left very distressed by what happened.
“If anyone saw anything or anyone suspicious in the area around the time of the burglary I would urge them to get in contact with me.
“I would particularly like to speak to anyone who saw three stocky white men, together with a taller skinny man, or any suspicious vehicles in the vicinity.
“I’m also keen to speak to any residents who were cold called either on that day or in the days prior to the burglaries taking place.”
Anyone with information is asked to contact DC Doyle via Hertfordshire Constabulary’s non-emergency number 101.
Alternatively call Crimestoppers anonymously on 0800 555 111.
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