Three classrooms were cordoned off and the the school closed for two days earlier this month after pipes had burst causing flooding.
Principal Tom Johnston said: "Burst pipes from older pipe work buried in the floor of the school caused us to lose heating in A Block and also caused some flood damage in the lowest lying area of the school by our drama studios.
"The pipe work below the drama area was tested as soon as the leak occurred and was found to contain asbestos. This is why we closed off this area of the school on the advice of the experts from Dudley Building Services, Health and Safety Hazards.
"We also carried out air testing to ensure that surrounding areas were safe.
"Having restored enough of the heating system to render the buildings usable we then gradually reopened for students."
He added: "The asbestos is being safely dealt with under the usual strict conditions and until this is complete the drama area will remain closed and sealed off.
"At no point was any student or member of staff exposed to risk during these events."
He added: "We continue to have heating difficulties in half a dozen rooms, but staff and students are managing this with their usual aplomb.
"I expect to have normal service fully resumed at some point during the next three weeks."
Belle Vale Councillor Donnella Russell whose child attends the school praised the staff.
She said: "The staff at the school have worked round the clock to ensure the children and school are safe.
"As a parent I did not hesitate to send my child back to the school as no child or staff has come to any harm."