The house on Soi Jiramakorn belongs to Police Lieutenant Colonel Kittikan Saengboon, 51, who discharged over 40 rounds into the air from a firearm on Tuesday afternoon.
Kittikan, a Special Branch inspector, reportedly has a history of mental illness.
Witnesses said they heard several gunshots being fired at around noon on Tuesday.
Residents in the neighbourhood have been evacuated.
As of press time there were no reports of injury or deaths.
Almost 20 hours of negotiations with the gunman came to an abrupt halt early on Wednesday morning when a Special Ops unit lobbed stun grenades into the house.
At 6.20am, the unit managed to gain access to the second floor of the house but was unable to reach Kittikan, who had locked himself in a room on first floor.
At 8.30am police armed with rubber-bullet guns gathered in a nearby soi to infiltrate the house from the side. Meanwhile negotiators continued to ask the suspect to put down his weapon and surrender.
Police also played Thai folk songs on loudspeakers in an attempt to calm the suspect down.
However, there was no response from the suspect on Wednesday morning.