In Prisoner of Azkaban Harry flees from the Dursleys after inflating his aunt. He quite literally LEAVES the house, apparently with no intent to come back but to live as an outcast in the Wizarding World.
Now the Bond of Blood charm which protects Harry breaks only under 2 conditions:
He should become 17 years of age,
He should leave the house and call it home no more.
In the situation I mentioned above, condition 2 has been breached. So why didn't the Bond of Blood charm break?