Used in the following models: 400, 701, 501, 801, 601, WH 55, WB 51, WH 85, WB 81, WH 110, WB 106, WH 155, WB 151, WH 199, WB 211, WH 285, WH 399, AW 151, AW 200, AW 286, AW 400, AW 501, AW 601, AW 701, AW 801, XP 400, XP 501, XP 601, XP 701, XP 801, KB 400, KB 501, KB 601, KB 701, KB 801, KB 81, KB 211, KB 106, KB 286, KB 151, Lochinvar Parts, Hydronic Heater Parts, Lochinvar, Lochinvar, Lochinvar, Knight, Floor Standing KB, Wall Mount WB & WH