Volunteer firefighters were called to the Pukehina home on Te Puke East Rd at 7.25am.
Chief fire officer Errol Watts said: "The pipes were ripped out of the hot water cylinder and there was substantial flooding in the home.''
Mr Watts said when they got to the address, the family had turned off the water mains and were attempting to mop up the excess water.
"They had plenty of towels down and they had managed to turn the water off ... but there was enough water to flood the carpet. The carpet will have to be lifted.''
No one in the household was injured.
Earthquakes are common in the Bay of Plenty region, including a destructive magnitude 6.5 quake in Edgecumbe, on March 2, 1987, which injured 25.