
Lennox 36W77 Pressure Switch
As a seasoned technician, you know that a failing 2 stage pressure switch can ground a high-efficiency furnace during the peak of the heating season. The Lennox 36W77 is a dual-stage assembly engineered specifically for variable capacity and modulating furnaces, such as the G71MPP series. This genuine HVAC OEM part features two distinct set points—a Low Fire stage at 0.25" W.C. and a High Fire stage at 1.22" W.C.—to ensure the inducer motor is moving sufficient combustion air before the gas valve opens. Replacing the 101599-04, this switch provides the precise air pressure regulation required to maintain certified system efficiencies. The robust construction is designed to withstand the vibration and thermal cycling of industrial and residential header boxes, making it a reliable Lennox furnace pressure switch replacement for contractors who prioritize first-time fix rates over marketing fluff.
Key Benefits- Dual-Stage Precision: Accurate monitoring of low and high fire combustion air requirements (0.25"/1.22" WC) for modulating systems.
- Exact OEM Fit: Direct replacement for part 101599-04, ensuring port alignment and wire connector compatibility.
- System Safety: Prevents furnace operation during venting obstructions or inducer motor failure, protecting the heat exchanger.
- Optimized Efficiency: Maintains factory-spec performance and sound levels by syncing with the unit’s control board logic.
What are the trip points for the Lennox 36W77?
This switch is calibrated for a 2-stage operation with a low-pressure set point of -0.25" W.C. and a high-pressure set point of -1.22" W.C.
Which Lennox models are compatible with this switch?
It is primarily utilized in G71MPP series furnaces, including G71MPP-36B, G71MPP-36C, and G71MPP-60C models.
What does a "Pressure Switch Stuck Open" code mean on a 2-stage unit?
It typically indicates the switch is not sensing enough vacuum from the inducer. Verify there are no cracks in the tubing or blockages in the flue before replacing the Lennox 36W77.
Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.
Original: $55.01
-65%$55.01
$19.25Lennox 36W77 Pressure Switch
As a seasoned technician, you know that a failing 2 stage pressure switch can ground a high-efficiency furnace during the peak of the heating season. The Lennox 36W77 is a dual-stage assembly engineered specifically for variable capacity and modulating furnaces, such as the G71MPP series. This genuine HVAC OEM part features two distinct set points—a Low Fire stage at 0.25" W.C. and a High Fire stage at 1.22" W.C.—to ensure the inducer motor is moving sufficient combustion air before the gas valve opens. Replacing the 101599-04, this switch provides the precise air pressure regulation required to maintain certified system efficiencies. The robust construction is designed to withstand the vibration and thermal cycling of industrial and residential header boxes, making it a reliable Lennox furnace pressure switch replacement for contractors who prioritize first-time fix rates over marketing fluff.
Key Benefits- Dual-Stage Precision: Accurate monitoring of low and high fire combustion air requirements (0.25"/1.22" WC) for modulating systems.
- Exact OEM Fit: Direct replacement for part 101599-04, ensuring port alignment and wire connector compatibility.
- System Safety: Prevents furnace operation during venting obstructions or inducer motor failure, protecting the heat exchanger.
- Optimized Efficiency: Maintains factory-spec performance and sound levels by syncing with the unit’s control board logic.
What are the trip points for the Lennox 36W77?
This switch is calibrated for a 2-stage operation with a low-pressure set point of -0.25" W.C. and a high-pressure set point of -1.22" W.C.
Which Lennox models are compatible with this switch?
It is primarily utilized in G71MPP series furnaces, including G71MPP-36B, G71MPP-36C, and G71MPP-60C models.
What does a "Pressure Switch Stuck Open" code mean on a 2-stage unit?
It typically indicates the switch is not sensing enough vacuum from the inducer. Verify there are no cracks in the tubing or blockages in the flue before replacing the Lennox 36W77.
Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.
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Description
As a seasoned technician, you know that a failing 2 stage pressure switch can ground a high-efficiency furnace during the peak of the heating season. The Lennox 36W77 is a dual-stage assembly engineered specifically for variable capacity and modulating furnaces, such as the G71MPP series. This genuine HVAC OEM part features two distinct set points—a Low Fire stage at 0.25" W.C. and a High Fire stage at 1.22" W.C.—to ensure the inducer motor is moving sufficient combustion air before the gas valve opens. Replacing the 101599-04, this switch provides the precise air pressure regulation required to maintain certified system efficiencies. The robust construction is designed to withstand the vibration and thermal cycling of industrial and residential header boxes, making it a reliable Lennox furnace pressure switch replacement for contractors who prioritize first-time fix rates over marketing fluff.
Key Benefits- Dual-Stage Precision: Accurate monitoring of low and high fire combustion air requirements (0.25"/1.22" WC) for modulating systems.
- Exact OEM Fit: Direct replacement for part 101599-04, ensuring port alignment and wire connector compatibility.
- System Safety: Prevents furnace operation during venting obstructions or inducer motor failure, protecting the heat exchanger.
- Optimized Efficiency: Maintains factory-spec performance and sound levels by syncing with the unit’s control board logic.
What are the trip points for the Lennox 36W77?
This switch is calibrated for a 2-stage operation with a low-pressure set point of -0.25" W.C. and a high-pressure set point of -1.22" W.C.
Which Lennox models are compatible with this switch?
It is primarily utilized in G71MPP series furnaces, including G71MPP-36B, G71MPP-36C, and G71MPP-60C models.
What does a "Pressure Switch Stuck Open" code mean on a 2-stage unit?
It typically indicates the switch is not sensing enough vacuum from the inducer. Verify there are no cracks in the tubing or blockages in the flue before replacing the Lennox 36W77.
Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.












