WARRANTY. Found system blowing warm air upon arrival. Customer said unit has been blowing warm air for about two weeks. Checked power from sub panel and reset. Outdoor unit still did not fire on. Checked for power and unit is calling for cooling but unit is not engaging. Found open error code for low pressure. Reset. Found system low on charge. Added freon and leak seal and dye. Need to come back in 2-3 weeks to search for leak. Unit operational upon departure.