Firefighters were called to reports of ‘helicopter’ noises in a loft at sheltered accommodation last night.
Worried residents were keen to identify the cause and called firefighters to Griffin Court, the Warren, Ashtead, at 9.30pm.
It is emerged that the noise was probably due to a water hammer - a pressure surge that spreads though pipes when a valve closes suddenly at the end of the system.
A firefighter said: "I think one woman in particular was concerned because she had been involved in fires before.
"The resident compared it to the sound of a helicopter.
"The noise sounded like an engine in the loft space. It was making a hell of a racket."