Why is my unit heater making a rattling noise

By utilizing brushless DC motor technology

and MHC20RMBBEC1

As a direct replacement for the Carrier 48TJ500-070

Sanyo HVAC CWA747077 PC Board 320819-301 Why is my unit heaterThe Sanyo HVAC CWA747077 PC Board is a critical OEM replacement component designed to restore precise logic control and communication to your ductless mini split or multi zone system. As a veteran technician knows, the printed circuit board (PCB) acts as the central processor, managing essential parameters including compressor frequency, fan motor speeds, and thermal expansion valve (TXV) positioning. Replacing a faulty board with a genuine Sanyo