5" insertion Fan and Limit Controller with 125 F fan on/100 F fan off, 200 F high limit

The Honeywell L4064B2228 Fan and Limit Controller provides dependable temperature regulation and safety protection for warm air furnace systems.

Designed for accurate fan control and overheat protection, the Honeywell L4064B2228 combines fan and limit functions in one compact, durable unit. With a 5-inch insertion element, it senses plenum temperature to control blower fan operation and act as a high-limit safety cutoff. Factory-set fan and limit temperatures ensure reliable performance, system safety, and occupant comfort.

• Model number L4064B2228 identifies the Honeywell Fan and Limit Controller featuring a 5-inch insertion element with fixed temperature settings.
• Designed for warm air furnaces to regulate blower operation and provide high-temperature limit protection.
• Combines fan control and limit safety control functions into one precision-engineered device.

Technical Data & Performance

• Product Type: Fan and Limit Controller.
• Element Length: 5 inches – suitable for compact furnaces and standard residential plenum installations.
• Fan Control Settings: Fan On: 125°F (52°C); Fan Off: 100°F (38°C).
• High Limit Setting: 200°F (93°C) – automatically shuts off the burner to prevent overheating.
• Switch Configuration: SPST fan switch / SPST limit switch combination for dual control functionality.
• Electrical Ratings: Supports 8A at 120V AC (resistive load); suitable for standard furnace fan and burner circuits.
• Application: Controls blower fan operation and serves as a high-limit safety cutoff in warm air furnaces.
• Sensing Element: Coiled bimetal sensor designed for precise temperature response and long-term stability.
• Differential: Factory-set fan differential for optimized blower cycling and comfort.
• Construction: Metal sensing element with a durable plastic enclosure for temperature stability and reliability.
• Mounting Type: Surface mount with insertion probe extending into furnace plenum for direct temperature sensing.
• Reset Type: Manual reset on high limit for additional system safety.
• Operating Voltage: 120V AC standard.
• Ambient Temperature Range: -40°F to 190°F (-40°C to 88°C).
• Function: Turns blower on when plenum reaches set temperature, turns it off when cooled, and shuts down burner at high limit.
• Safety Function: Prevents heat exchanger damage and furnace overheating by cutting power to the burner when limit temperature is exceeded.
• Installation: Simple retrofit or OEM installation with accessible adjustment dials and secure terminal connections.
• Compliance: Meets UL and CSA standards for HVAC system safety controls.
• Maintenance: Low-maintenance design; inspect periodically during furnace servicing.
• Dimensions: 5-inch insertion length; standard control housing with adjustable mounting bracket.
• Warranty: Backed by Honeywell’s Limited Manufacturer’s Warranty for performance and reliability.