Found Reach-In Freezer drain line froze up, Put unit into defrost and defrost coils are working and drain line heater has power going to it but not getting warm, Checked heater and is open reading, Unit will need a new drain line heater, Talked with Michael at Minus Forty tech support and part number for drain line heater is #1291, customer would like a quote on the completion of this. 3/7/19 Removed evap cover and drip tray. tried to pull old drain heater but could not. it''s stuck inside drain line. I opened other end of drain line. blew out with nitrogen but nothing. probably drain line is iced up. I poured hot water little by little still could not pull drain heater. manager decided to let unit sit overnight and we will come back tomorrow. I left all parts of unit unscrewed. screws are in plastic bag.