Lennox 78L29 / 78L2901 Flame Rollout Switch

Specifications

• Brand: Lennox
• Catalog Number: 78L29
• Model / Part Number: 78L2901
• Product Type: Flame Rollout Limit Switch
• Reset Type: Manual Reset
• Actuation Temperature: 250°F
• Switch Type: SPST
• Colour Identification: Blue
• UPC: 66255135674
• Application: Gas furnace safety control

Lennox identifies the 78L29 / 78L2901 as a manual-reset rollout switch that actuates at 250°F.

Replacement & Cross-Reference Part Numbers

• 78L29
• 78L2901

The catalog number 78L29 and model/part number 78L2901 identify the same Lennox rollout control.

Lennox 78L29 Flame Rollout Switch

The Lennox 78L29 is a manual-reset furnace safety switch designed to open the safety circuit if excessive heat or flame rollout is detected in the burner area.

The switch is normally part of the furnace safety circuit. If the temperature at the switch reaches approximately 250°F, the switch opens and interrupts furnace operation.

Because the 78L29 is a manual-reset rollout switch, a tripped switch should not simply be repeatedly reset. The furnace should be inspected to determine why the rollout switch opened.

Compatible Lennox Furnace Models

The 78L29 is used in numerous Lennox furnace models, including:

• G40UH-24A-045
• G40UH-24A-070
• G40UH-36A-045
• G40UH-36A-070
• G40UH-36B-090
• G40UH-36C-110
• G40UH-48B-070
• G40UH-48B-090
• G40UH-48C-110
• G40UH-60C-110
• G43UF-24B-045
• G43UF-24B-070
• G43UF-36B-070
• G43UF-36C-090
• G43UF-48C-090
• G43UF-48C-110
• G43UF-60C-110
• G43UF-60D-135
• G50UH-24A-045
• G50UH-24A-070
• G50UH-36A-070
• G50UH-36B-090
• G50UH-36C-110
• G50UH-48B-070
• G50UH-48B-090
• G50UH-48C-110
• G50UH-60C-110
• G51MP-24B-045
• G51MP-36B-045
• G51MP-36B-070
• G51MP-36C-090
• G51MP-48C-090
• G51MP-48C-110
• G51MP-60C-090
• G51MP-60C-110
• G51MP-60D-135
• G60UH-24A-070
• G60UH-36A-070
• G60UH-36B-090
• G60UH-36C-110
• G60UH-48B-090
• G60UH-48C-110
• G60UH-60C-110
• G61MP-36B-045
• G61MP-36B-070
• G61MP-48C-090
• G61MP-48C-110
• G61MP-60C-090
• G61MP-60C-110
• G61MP-60D-135
• G61MPV-36B-045
• G61MPV-36B-070
• G61MPV-36C-090
• G61MPV-60C-090
• G61MPV-60C-110
• G61MPV-60D-135
• G71MPP-36B-070
• G71MPP-36C-090
• G71MPP-60C-090
• G71MPP-60C-110
• G71MPP-60D-135

These applications are documented for the 78L29 rollout switch.

Common Signs of a Tripped or Failed Rollout Switch

• Furnace will not ignite
• Burners shut down shortly after ignition
• Furnace enters safety lockout
• No continuity through the rollout switch
• Manual-reset button has tripped
• Furnace repeatedly shuts down during a heating call

A rollout switch that repeatedly trips can indicate a combustion, burner, venting or heat-exchanger problem. The cause should be diagnosed rather than bypassing the safety switch.

Buy Lennox 78L29 Rollout Switch in Canada

Buy the Lennox 78L29 / 78L2901 250°F Manual Reset Flame Rollout Switch from OemHvacPartsCanada.ca.