Teledyne Laars 10098905 Cupronickel Heat Exchanger, 18 Tube Assembly, with glass-lined tubs, 4050I (indoor), 3600E (outdoor), Previous Part #20098905
Used on the following models:
AP3600, AP4050, HH3600, HH4050, PH3600, PH4050, PW3600, PW4050, VW3600, VW4050,
MT3600, MT4050.