Harman & Heatilator Genuine OEM Vacuum Pressure Differential Switch, Part Number 3-20-6866

The Differential switch is one of the safeties that Pellet stove companies install into their stoves | If the stove is not reaching the correct pressure it could point to an issue that needs to be addressed before the stove can function safely | The differential switch will not allow the stove to feed pellets if there is a blockage or air leak