Performed preferred customer furnace cleaning. Cleaned the burners and the flame sensor. Checked the heat exchanger. Wiped down the inside of the furnace. Checked the electrical. Cycled the furnace and performed a furnace combustion test. The furnace is running normally at this time. Performed preferred customer air conditioning cleaning. Checked the indoor coil for leaks. Did not find a leak at this time. Cleaned the condenser unit. Checked the electrical. Cycled the air conditioner and checked the refrigerant levels. Found that the air conditioner is running low on 410a refrigerant. The customer would like to wait until spring and then have an air conditioner cleaning to recheck the pressures. Office to call in the spring to schedule the cleaning.