ISV100 not stopping at set temp

I have used my ISV100 for about 1 1/2 years with no problem. This time when I set the temperature to 115F it just keeps getting hotter. What could be the problem

Hello,
Please check whether the water circulation at the bottom is working. If the water circulation does not work, please gently remove the plastic bottom cover at the bottom and check whether the screws of the water blade are loose/whether the shaft of the water blade is offset and touches the stainless steel cylinder.
If the screw is loose, please tighten the screw.
If the water blade axis is offset and touches the stainless steel cylinder, please try to push it so that it does not touch the stainless steel cylinder. It is normal for the water blade axis to slightly deviate but not touch the stainless steel cylinder.
ISV-100W has a one-year warranty. If it still has problems, please provide the order information and the problem video to email support@inkbird.com for after-sales service.
Thanks.