Upon arrival tech was informed thermostat in kitchen was not cooling. Thermostat is set to 70 reading 84. Inspected system and found duct detector tripped in system shutting it down. Reset duct detector and system came on. Suspects it tripped due to potential smoke from grill near return. Tech did observe both exhaust fans working. Informed customer it will take a few hours to bring temp back down. System is back operational at this time.