Used in the following models: 501, 991, 1801, 651, 1261, 2071, 751, 1441, 400, 701, 501, 801, 601, FB 1500, FB 2000, FB 2500, FB 3000, FB 3500, AW 1000, AW 1300, AW 1500, AW 151, AW 200, AW 286, AW 400, AW 501, AW 601, AW 701, AW 801, XP 1015, XP 1320, XP 1520, XP 400, XP 501, XP 601, XP 701, XP 801, 502, 652, 752, 992, 1262, 1442, 1802, 2072, KB 400, KB 501, KB 601, KB 701, KB 801, KB 80, KB 105, KB 150, KB 210, KB 285, KB 399, KB 500, KB 600, KB 700, KB 800, AW 150, AW 199, AW 285, AW 399, AW 500, AW 600, AW 700, AW 800, SB 1000, Sync, SB 1300, SB 1500, KB 81, KB 211, KB 106, KB 286, KB 151, CB 497, CW 497, CB 647, CW 647, CB 747, CW 747, CB 987, CW 987, CB 1257, CW 1257, CB 1437, CW 1437, CB 1797, CW 1797, CB 2067, CW 2067, PB 502, PF 502, PB 752, PF 752, PB 1002, PF 1002, PB 1302, PF 1302, PB 1501, PF 1501, PB 1701, PF 1701, PB 2001, PF 2001, CH 401, 401, CH 501, 501, CH 651, 651, CH 751, 751, CH 402, 402, CH 502, 502, CH 652, 652, CH 752, 752, CH 991, 991, CH 1261, 1261, CH 1441, 1441, CH 1801, 1801, CH 2071, 2071, CH 992, 992, CH 1262, 1262, CH 1442, 1442, CH 1802, 1802, CH 2072, 2072, PB 501, PF 501, PB 751, PF 751, PB 1001, PF 1001, PB 1300, PF 1300, CB 986, CW 986, CB 1256, CW 1256, CB 1436, CW 1436, CB 1796, CW 1796, CB 2066, CW 2066, Lochinvar Parts, Hydronic Heater Parts, Lochinvar, Lochinvar, Lochinvar, Knight, Floor Standing KB, Pool Heater Parts