Compare Quick view Watkins Watkins | PCB | IQ 2020/ADVENT HEATER CONTROL BOARD | 74618 MSRP: Was: Now: $257.55 Watkins | PCB | IQ 2020/ADVENT HEATER CONTROL BOARD | 74618 This heater relay board retrofits into IQ-2020 & Advent controls. Item #74618 is replacement option for 73355, 73357 Brand name : Watkins Add to Cart Add to Cart