The Honeywell RTH230B indicates that the system is running the overnight (sleep) program with the 4 inside the house symbol. When the house flashes, the desired temperature has been changed from that programmed temperature (bypass mode). The bypass mode should only run for 2 hours.
The default programming starts the sleep period at 10 P.M. and ends at 6 A.M. On the original program in the thermostat, the temperature target was set to 62 during the heating season and 82 for the air conditioning season.
Since the thermostat was set to bypass, you should check who in your house pressed the Up/Down buttons on the thermostat to change the house temperature. Beyond that, check the start and end times and the programmed temperatures for each scheduled period. Honeywell has the manual for the RTH230B here: https://customer.honeywell.com/resources/techlit/TechLitDocuments/69-0000s/69-1800.pdf
I hope this helps
(On my own programmable thermostat, we recently found that one period in the week had been left at the default setting. Thus the thermostat was programmed to maintain 60 degrees when we wanted 65 during the day.)