Lennox 78H74 Limit Switch
The Lennox 78H74 is a critical OEM L185F limit switch designed for precision thermal protection in residential and commercial Lennox heating systems. As a primary safety control, this high-limit switch monitors internal heat exchanger temperatures and is engineered to open the electrical circuit if the ambient temperature reaches the L185°F set point. This rapid response prevents internal overheating and ensures the system operates within safe HVAC furnace specifications. Built for durability and accurate sensing, the Lennox 78H74 limit control features standard quick-connect terminals for a secure electrical interface and a surface-mount design for direct integration into the heat zone.
For technicians performing maintenance or emergency repairs, the Lennox 78H74 is the drop-in replacement for Lennox 78H7401, maintaining the original equipment’s safety ratings and system efficiency. It is compatible with a wide range of Lennox units, including the ECH16, ECH24, and EHA series air handlers and electric heat sections. Utilizing genuine Lennox HVAC replacement parts ensures that the safety circuit remains calibrated to the manufacturer's exact thermal thresholds, preventing nuisance trips while providing reliable protection against equipment damage.
Key Benefits- Precise Thermal Calibration: Factory-set to trip at 185°F (L185F) to safeguard the heat exchanger and surrounding components.
- Direct OEM Compatibility: Engineered specifically for Lennox models like the ECH16-15-02 and EHA-072-25-01, ensuring a perfect physical and electrical fit.
- Enhanced System Safety: Actively prevents furnace overheating by interrupting power to the heating element when safety limits are exceeded.
- Industrial-Grade Build: Designed for high-heat environments with quick-connect terminals for simplified field installation.
What causes a Lennox 78H74 limit switch to trip?
A trip is usually the result of restricted airflow caused by a dirty air filter, a failing blower motor, or obstructed ductwork, leading to localized overheating.
Can I use a different temperature-rated switch as a substitute?
No. To maintain the safety listing and equipment integrity, always replace a L185F switch with an identical L185F rated 78H74 control.
How do I verify if my Lennox air handler requires this specific part?
Check the data plate on your unit or the existing switch. This part is a standard high-limit for various Lennox ECH and EHA series electric heat sections.
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: $53.48
-65%$53.48
$18.72Lennox 78H74 Limit Switch
The Lennox 78H74 is a critical OEM L185F limit switch designed for precision thermal protection in residential and commercial Lennox heating systems. As a primary safety control, this high-limit switch monitors internal heat exchanger temperatures and is engineered to open the electrical circuit if the ambient temperature reaches the L185°F set point. This rapid response prevents internal overheating and ensures the system operates within safe HVAC furnace specifications. Built for durability and accurate sensing, the Lennox 78H74 limit control features standard quick-connect terminals for a secure electrical interface and a surface-mount design for direct integration into the heat zone.
For technicians performing maintenance or emergency repairs, the Lennox 78H74 is the drop-in replacement for Lennox 78H7401, maintaining the original equipment’s safety ratings and system efficiency. It is compatible with a wide range of Lennox units, including the ECH16, ECH24, and EHA series air handlers and electric heat sections. Utilizing genuine Lennox HVAC replacement parts ensures that the safety circuit remains calibrated to the manufacturer's exact thermal thresholds, preventing nuisance trips while providing reliable protection against equipment damage.
Key Benefits- Precise Thermal Calibration: Factory-set to trip at 185°F (L185F) to safeguard the heat exchanger and surrounding components.
- Direct OEM Compatibility: Engineered specifically for Lennox models like the ECH16-15-02 and EHA-072-25-01, ensuring a perfect physical and electrical fit.
- Enhanced System Safety: Actively prevents furnace overheating by interrupting power to the heating element when safety limits are exceeded.
- Industrial-Grade Build: Designed for high-heat environments with quick-connect terminals for simplified field installation.
What causes a Lennox 78H74 limit switch to trip?
A trip is usually the result of restricted airflow caused by a dirty air filter, a failing blower motor, or obstructed ductwork, leading to localized overheating.
Can I use a different temperature-rated switch as a substitute?
No. To maintain the safety listing and equipment integrity, always replace a L185F switch with an identical L185F rated 78H74 control.
How do I verify if my Lennox air handler requires this specific part?
Check the data plate on your unit or the existing switch. This part is a standard high-limit for various Lennox ECH and EHA series electric heat sections.
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
The Lennox 78H74 is a critical OEM L185F limit switch designed for precision thermal protection in residential and commercial Lennox heating systems. As a primary safety control, this high-limit switch monitors internal heat exchanger temperatures and is engineered to open the electrical circuit if the ambient temperature reaches the L185°F set point. This rapid response prevents internal overheating and ensures the system operates within safe HVAC furnace specifications. Built for durability and accurate sensing, the Lennox 78H74 limit control features standard quick-connect terminals for a secure electrical interface and a surface-mount design for direct integration into the heat zone.
For technicians performing maintenance or emergency repairs, the Lennox 78H74 is the drop-in replacement for Lennox 78H7401, maintaining the original equipment’s safety ratings and system efficiency. It is compatible with a wide range of Lennox units, including the ECH16, ECH24, and EHA series air handlers and electric heat sections. Utilizing genuine Lennox HVAC replacement parts ensures that the safety circuit remains calibrated to the manufacturer's exact thermal thresholds, preventing nuisance trips while providing reliable protection against equipment damage.
Key Benefits- Precise Thermal Calibration: Factory-set to trip at 185°F (L185F) to safeguard the heat exchanger and surrounding components.
- Direct OEM Compatibility: Engineered specifically for Lennox models like the ECH16-15-02 and EHA-072-25-01, ensuring a perfect physical and electrical fit.
- Enhanced System Safety: Actively prevents furnace overheating by interrupting power to the heating element when safety limits are exceeded.
- Industrial-Grade Build: Designed for high-heat environments with quick-connect terminals for simplified field installation.
What causes a Lennox 78H74 limit switch to trip?
A trip is usually the result of restricted airflow caused by a dirty air filter, a failing blower motor, or obstructed ductwork, leading to localized overheating.
Can I use a different temperature-rated switch as a substitute?
No. To maintain the safety listing and equipment integrity, always replace a L185F switch with an identical L185F rated 78H74 control.
How do I verify if my Lennox air handler requires this specific part?
Check the data plate on your unit or the existing switch. This part is a standard high-limit for various Lennox ECH and EHA series electric heat sections.
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.
