A family's heating oil tank containing more than 800 litres was drained by thieves in Suffolk early on Christmas Day, police said.
The raid at Parkhill north of Lowestoft happened at about 0100 GMT.
As oil prices are now £1.23 a litre, the value of the theft is nearly £1,000.
The tank is visible from the road and police appealed to anyone travelling near Oulton and the A12 and saw anything suspicious to contact them.
Other Suffolk residents are also being urged to secure their heating oil.