Armstrong / Ducane Roll Out Switch 47K18

Armstrong Ducane Lennox 47K18 Flame Rollout Safety Switch

Protect your property and ensure safe heating operation with the genuine Armstrong, Ducane, Lennox 47K18 Flame Rollout Switch. This premium Factory Authorized Part is a critical fire-safety control engineered specifically for gas furnaces across the Lennox family of brands. Positioned near the burner vestibule, this sensor constantly monitors for flame rollout conditions—instantly breaking the 24V control circuit to shut down the main gas valve if burning gas escapes the heat exchanger.

As a genuine OEM component, the Lennox 47K18 Switch features a manual reset button, ensuring that if a dangerous thermal event occurs, the furnace remains completely locked out until a qualified technician can safely inspect the heat exchanger.

Technical Specifications:

  • Model/Part Number: 47K18
  • Control Type: Manual Reset Flame Rollout Safety Switch
  • Contact Configuration: SPST (Single Pole Single Throw, Normally Closed)
  • Voltage Compatibility: 24 VAC Control Circuit
  • Temperature Rating: 400°F (Precision Calibrated Thermal Disc)
  • Connections: Standard Quick-Connect Spade Terminals

Key Features & Benefits:

  • Genuine OEM Safety Engineering: Calibrated to open at exact factory-specified temperature thresholds. Unlike cheap generic safety switches that may drift out of spec, this original part guarantees your gas valve closes immediately when a rollout condition is detected.
  • Essential Flame Safeguard: Acts as your furnace's frontline defense against severe issues like a cracked heat exchanger, a blocked flue vent, or heavily fouled burners that force flames out of the combustion box.
  • Tamper-Resistant Manual Reset: Features a manual reset button. If the switch trips, it cannot automatically restart the furnace on its own, preventing repeating unsafe ignition attempts.
  • Rugged, Heat-Resistant Design: Built with a premium bimetal thermal disc and heavy-duty housing to withstand the intense ambient heat inside the furnace cabinet without false-tripping.

Compatibility & Cross-Reference

The 47K18 safety switch updates and modifies older furnace configurations. It is a verified direct fit and replacement for:

  • Obsolete Part Numbers: R37520B005.
  • Brand Compatibility: Direct OEM fit for residential gas furnaces labeled under Lennox, Armstrong Air, Ducane, Allied Air, Concord, and AirEase.

Why Buy From Shortys HVAC Supplies?

At Shortys HVAC, we offer only Original Equipment Manufacturer (OEM) factory parts so your repairs meet strict safety standards, maintain mechanical reliability, and protect original equipment warranties. By purchasing this genuine Armstrong Air 47K18 Switch, you avoid the safety risks associated with universal aftermarket alternatives.

Shipping Information: We provide competitive, fast shipping rates across the continental United States, ensuring your critical safety controls arrive quickly to get your heating system running safely.

$30.00

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  • Model: 47K18
  • Manufactured by: Armstrong Parts
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