I just bought a 30 year old house that has a Carrier 58cva090-16 gas furnace in it. The second weekend I owned he house the outdoor temps dropped to 12 degrees below zero. Due to the cold weather I was keeping an eye on the temp in the house. Towards the end of the heat cycle the thermostat would go blank for almost a minute. I checked my thermostat (Carrier) and it didn't have a place for a battery. Thinking it was the thermostat I purchased a new Honeywell WiFi programmable thermostat and installed it. It did NOT have a battery back up. This one also went blank at the same time in the cycle. I've checked for a switch on the side of the furnace and everything appears to be turned on properly.

The furnace seems to be running properly. Do I need to be concerned about the display going blank?