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Your furnace is cutting off on high limit because of an airflow issue. When you reset the thermostat it resets the limit and lets it fire back up, but the limit is already close to tripping again so it doesn't take long to do it all over again.
The high limit senses the temperature inside the furnace's heat exchanger and if the air isn't being pushed out properly it will exceed this high limit temperature and the limit opens causing the burners to go off and the blower to continue running to push the built up air out. Once the heat exchanger is cooled to it's reset temperature it will allow the furnace to come back on or if you reset the thermostat or high voltage power it will reset this limit. Like I said though when you do this the temperature inside is already built up and the limit will trip again soon.
Things that cause this are a dirty filter, dirty evaporator coil underside, blocked return runs, blocked supply runs, malfunctioning blower motor that is not coming on and pushing air with the burners on, or simply a malfunctioning limit device or control board.
Most furnaces will give you a blink code on the LED of the control board telling you that it is cut off on a fualt