Detector: Overheat 'failed' after system check

Hello... I would like to seek your advice regarding the error/remarks I have been encountered on our GC2030 after almost 2 days of shutdown. System method temperature is only 280'c (max. 470'C), but every after diagnosis of system check, there was a remark of 'Overheat: Fail' under Heat sensor check. This is the first time I've encounter this problem. I am anxious to continue the start up because of this. Hoping for your kind assistance. Thank you so much