Pupils at Forfar Academy returned to freezing classrooms on Thursday morning after a major electrical fault.
The problems involving the school’s electrical supply came to light on Wednesday afternoon.
The school closed at 4pm so that SSE technicians could get to work on the overnight repair.
The problems meant a planned fifth and sixth year parents’ night was postponed.
Parents were updated with the work’s progress through the Forfar Academy Twitter feed.
It said: “Power supply now fixed and working. Thanks to team from SSE. School open though bit cold, as no heating overnight and the morning pretty frosty.
“Busy night for school janitors too. Big thank you to them also. A great team! Make their job easy today – bin all of your litter!”
