While outside I noticed there are several screws missing from the side panels of my Trane Weathertron XE1000 heat pump condenser. I removed one of the screws and it is an unslotted indented 5/16 inch hex head screw that appears to be galvanized and about 1/2 inch long. I guess this is what is considered a zip screw. I am not sure if it is a #8 or a #10 screw. It has a sharp point. Does anyone know where to buy replacement screws for this unit? I went to the local Home Depot and Lowe's but they don't have an exact match.