Lennox 12P55 Limit Switch
When you are dealing with a furnace that is short-cycling or hitting the high-limit threshold prematurely, the Lennox 12P55 Limit Switch (Model L190-30F) is the exact OEM replacement required to restore safe operation. This bimetallic disc limit switch is engineered to monitor heat exchanger temperatures, featuring a critical 190°F cutout setpoint and a 30°F differential for the reset. As a primary safety component in Lennox residential furnaces, it protects the heat exchanger by interrupting the 24V control circuit if airflow is restricted—commonly caused by a dirty furnace filter or a failing blower motor. This genuine Lennox replacement part ensures HVAC system safety and prevents expensive heat exchanger damage. Designed for a standard two-hole surface mount, the Lennox 102857-09 provides the precise thermal response needed for high-efficiency gas furnaces. Replacing a faulty L190-30F main limit switch resolves furnace error codes like E250 and stops the blower fan from running continuously when no heat is being called for.
Key Benefits- OEM Precision: Guaranteed compatibility with Lennox equipment, ensuring the 190-degree limit matches factory specifications.
- System Protection: Acts as a failsafe against overheating, preserving the integrity of the heat exchanger and internal components.
- Reliable Switching: Utilizes a high-grade bimetal element for consistent L190-30F switch performance over thousands of cycles.
- Direct Fit: Factory-drilled mounting holes allow for quick installation on the furnace plenum or blower housing.
What are the symptoms of a bad Lennox 12P55 limit switch?
Common indicators include the furnace shutting down before reaching the thermostat setpoint, the indoor blower motor running non-stop, or specific diagnostic flash codes related to an open high-limit circuit.
Does this switch require a manual reset?
No, the L190-30F is an automatic reset switch. It will close the circuit and allow the burners to reignite once the plenum temperature drops by its 30°F differential.
Why does my new limit switch keep tripping?
A tripped limit is often a symptom of an airflow obstruction. Check for a clogged air filter, blocked return air ducts, or a build-up of debris on the evaporator coil before assuming the switch itself is defective.
This item is not eligible for free shipping.
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: $12.01
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Description
When you are dealing with a furnace that is short-cycling or hitting the high-limit threshold prematurely, the Lennox 12P55 Limit Switch (Model L190-30F) is the exact OEM replacement required to restore safe operation. This bimetallic disc limit switch is engineered to monitor heat exchanger temperatures, featuring a critical 190°F cutout setpoint and a 30°F differential for the reset. As a primary safety component in Lennox residential furnaces, it protects the heat exchanger by interrupting the 24V control circuit if airflow is restricted—commonly caused by a dirty furnace filter or a failing blower motor. This genuine Lennox replacement part ensures HVAC system safety and prevents expensive heat exchanger damage. Designed for a standard two-hole surface mount, the Lennox 102857-09 provides the precise thermal response needed for high-efficiency gas furnaces. Replacing a faulty L190-30F main limit switch resolves furnace error codes like E250 and stops the blower fan from running continuously when no heat is being called for.
Key Benefits- OEM Precision: Guaranteed compatibility with Lennox equipment, ensuring the 190-degree limit matches factory specifications.
- System Protection: Acts as a failsafe against overheating, preserving the integrity of the heat exchanger and internal components.
- Reliable Switching: Utilizes a high-grade bimetal element for consistent L190-30F switch performance over thousands of cycles.
- Direct Fit: Factory-drilled mounting holes allow for quick installation on the furnace plenum or blower housing.
What are the symptoms of a bad Lennox 12P55 limit switch?
Common indicators include the furnace shutting down before reaching the thermostat setpoint, the indoor blower motor running non-stop, or specific diagnostic flash codes related to an open high-limit circuit.
Does this switch require a manual reset?
No, the L190-30F is an automatic reset switch. It will close the circuit and allow the burners to reignite once the plenum temperature drops by its 30°F differential.
Why does my new limit switch keep tripping?
A tripped limit is often a symptom of an airflow obstruction. Check for a clogged air filter, blocked return air ducts, or a build-up of debris on the evaporator coil before assuming the switch itself is defective.
This item is not eligible for free shipping.
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.
