Police were alerted to the burglary at the BP service station on Wainuiomata Road just before 2.30am.
Officers, including a dog handler, were in the area soon after however were unable to locate any offenders at the time, police said.
The excavator was unlawfully taken from a nearby construction site, police said.
The building was deemed unstable so a scene guard was in place overnight.
Wainuiomata shopkeeper Amit Patel was increasing security at his store after seeing the ram raid, which had made him nervous that the same thing might happen to his shop.
The Super Save Supermarket owner had asked also friends who had stores ram-raided in Waikanae and Paraparaumu for advice.
"It's happening quite badly now," he said. "Literally I just ran my security guy."
"We are treating this matter seriously and we believe someone in the close knit Wainuiomata community will know who did this," Hutt Valley prevention manger Inspector Haley Ryan said.
Staff would go door-to-door speaking to any potential witnesses or anyone with relevant information.
ANZ Bank has an ATM at the site and said while it was damaged, it wasn't broken into.
