Hello I am here to assist you.
Have you removed the thermostat cover to check to see if it uses batteries?
If it does, change them out. It may have dead batteries.
Please hit ACCEPT if you are satisfied with this answer. If not, I will continue to assist you. Bonuses and positive feedback are very much appreciated!
How do I remove the cover?
I tried to remove it --- and removed the whole unit by accident. I suppose you didn't know that TOTALINE 0441 does not have any batteries....
This is not a battery issue (obviously) it is the furnace running on limit or another safety which in turn cuts power to the thermostat. Then when cooled it magically gets power again.
Check the air filter first...the blower to make sure it runs consistently, and for any obstructions that could cause diminished air flow.
Check those things and let me know.