Hi,
90 is the highest allowed setpoint, can you get the setpoint to go any lower ?
If you can not then the thermostat is defective, if it is not turning your equipment off with a 90 degree setpoint the thermostat is defective, so you will end up replacing it.
Thanks
Mark
I'm sorry but there probably is no help for it. I can get you the manual if you don't have it but there isn't much in there and nothing that covers this exact situation. Typically if it is a scenario that is not in the troubleshooting section of the manual then it means its a defective part.
Journeyman Technician
UA Journeyman Pipefitter , HVAC, Refrigeration, DDC controls. 26 years.Commercial & residential