Lennox 90W84 Hot Water Heat Kit Hot water heat kit (90W84) adapts CBX32MV and CBX40UHV units for use with a boiler to provide hot water heating in select applications. When used with an air conditioner, the hot water provides first-stage heating. When used with a heat pump, the hot water provides second-stage heating Controls a third-party hot water boiler with a hot water heating coil installed downstream from the air handler Kit contains all necessary relays and plug-in wiring harness to control boiler Includes: DC Relay, 22VDC 102297-01 3PDT Relay 67K6601 Delay-On-Make Relay 99P41 9-Pin Wiring Harness 609345-01 Wiring Diagram 537516-01 NOTE - This kit is only approved for use in systems using a Lennox Communicating thermostat or a CS7500 thermostat.