My thermostat was reading a correct temperature of 74 degrees then went down suddenly to 40d it's that that cold in my house, I live in Florida, what's up with that?

Why is my temperature reading 40 degrees lower than it should, this happened suddenly model 1F82-261.

My model thermostat model is 1F82-261 the temperature suddenly went down 40 degrees on my thermostat, it was reading 74 which was correct, Why?

Sounds like for some reason the stat is reading in celsius instead of fahrenheit. You will need the stat instructions to get it set back to F. Either this or your stat is shot.

Hi. This is Aaron Moratalla from White Rodgers. For 1F82-261, press the reset button inside. Pull the front cover off to locate the circuit board. Look below fan switch and press the reset button. The screen should blank out momentarily and when it goes back it will give you a normal operation. If you need more help please don't hesitate to call our tech line at 800-284-2925. Thank you for choosing White Rodgers!

Hey Aaron. Thank YOU for taking the time to help out here at AMHD. Great info, and awesome for you to leave your tech number. Hope to see you around on the heating forum. Take care.