A spokesman told Utility Week the company had responded “very quickly” to the problem, and the vast majority of supplies had returned to normal that afternoon.
However, “a very small number” of people had air locks in the system once pressure was restored, he added. “We helped them individually.”
Just weeks earlier, Thames Water came under criticism from London Mayor Sadiq Khan when hundreds of properties in Stoke Newington and Blackheath were flooded after water pipes burst.
Water regulator Ofwat said the incidents could affect a number of the company’s performance commitments, such as asset health water infrastructure; service incentive mechanism; and customer satisfaction surveys.
A spokeswoman for Ofwat told Utility Week: “We do not know for definite the impact on Thames Water’s , as it depends on the precise nature of the bursts – how long customers were without supply, how much water leaked, what the impact on customer satisfaction was.”
Thames director Bob Collington told the BBC he was “absolutely devastated about the damage”, but denied the company was unprofessional.
He said the firm had been “in the process of applying for the permits” to close the road in Stoke Newington to fix the mains. In relation to Blackheath, he said that it can take “several hours to shut down one of these large pipes” to reduce disruption to other companies.
“We understand fully the consequences of getting it wrong and we take that really, really seriously,” he said.
The company said a full investigation will take place “to reduce the risk of further disruption”.