Hydronic Interface Relay Kit 12 Pin for Communicating Fan Coils FE5B

The Hydronic Interface Relay Kit 12 Pin for Communicating Fan Coils FE4B/FE5B (AFAINTHWC01A) provides the required control interface to operate a hydronic heating coil from an FE5B communicating fan coil by converting the variable-speed communicating heat call into a clean, low-voltage dry-contact output for pumps or zone valves. The kit includes a relay and rectifier control board, a prewired 12-pin harness sized to fit FE4B electrical architecture, low-voltage output leads for hydronic actuation, and mounting hardware designed for installation inside the fan coil’s control compartment. Its compact board layout and keyed harness ensure proper orientation so technicians maintain full communicating operation while gaining a stable hydronic heat call point without custom relay boxes. For job fit, verify the air handler is an FE4B communicating model and that the hydronic zone features a low-voltage control interface. Once confirmed, this relay kit provides a clean, documented installation pathway that improves system reliability and reduces troubleshooting time on dual-fuel and hydronic-assist applications.