McDonnell & Miller 309000 Resistor Kit 30067439-890 By utilizing this well

By utilizing this well

but if the ceramic is scorched or cracked

visible pitting on the contact surfaces

these parts are technically identical and can be used interchangeably in any Lennox application requiring a 120V to 24V step-down

2 Degree Differential

McDonnell & Miller 309000 Resistor Kit 30067439-890 By utilizing this wellThe McDonnell & Miller 309000 Resistor Kit, specifically the Model 7B 1R, is a critical slide wire resistor assembly engineered for proportional signal control in industrial boiler systems. This 135 ohm resistor kit is designed to interface directly with 7B switches, providing the necessary modulating signal for precise burner control and water level management. As a veteran grade replacement part, it is compatible with the Series 93, Series 193,