Up to six clinics at once had to close on some days because of high temperatures, even when the weather outside was mild, leading to hundreds of clinical appointments at the University of Otago Faculty of Dentistry being rescheduled.
Recently, clinics on March 19, 20, 21, 22 and 25 were closed, and there were also a string of closures earlier in the month.
A spokeswoman said yesterday some ''investigative work'' revealed a faulty steam valve was to blame.
The faulty valve was first discovered in November last year, but because of the expected refurbishment of the building it was not replaced.
''The heat was redirected to floors that were anticipated to be empty,'' she said.
''However, due to the fluid logistics of the renovation, the fourth floor remained in use longer than expected. This has resulted in the unfortunate instances of overheating.''
The university had stopped redirecting the heat and another solution for the valve fault was being sought.
''The closures of the building were regretfully inconvenient for many people, and the situation will be monitored to avoid any repetition.''
The temperature inside the clinics is recorded, and 30degC is the temperature at which the health and safety compliance team is notified.
Faculty dean Alison Rich said last month procedures could be stressful, and when heat stress was added they could have a negative impact on patient safety and wellbeing.
