Harman and Heatilator Vacuum Differential Switch
Genuine OEM replacement vacuum differential switch for Harman and Heatilator Eco-Choice pellet and coal stoves. The replacement vacuum differential switch is used in all Harman pellet stove models, the Harman Mark I coal stove model, and Heatilator Eco-Choice boiler and furnace models including the BA100, BH105, BH60, and BIO-120. Also referred to as the negative pressure switch or low draft switch, the vacuum differential switch senses air pressure in the firebox and exhaust flue vent pipe. The vacuum switch is in-line with the auger feed motor and will not allow the auger motor to run if it is tripped or faulty. Any air losses or air blockages can trip the vacuum switch. When experiencing issues with this safety switch, check the following: vacuum switch hose/tubing, firebox door and ash door gasket seals, ash accumulation in the stove or venting, air intake channel, combustion blower/exhaust fan functionality. HHT part numbers 3-30-6866 and SRV8320-003. Check out our video below to learn more about the pressure switch.
Genuine OEM Harman Replacement
Vacuum Pressure Differential Switch
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