Honeywell, L4006E1067/U, High Limit Aquastat, Manual Reset

Honeywell L4006E1067/U – High Limit Aquastat Controller with Manual Reset

The Honeywell L4006E1067/U is a high limit aquastat controller designed to monitor and control liquid temperature in hydronic heating systems. It features a manual reset function for safety-critical applications, ensuring burner shutdown in the event of a temperature overrun. This model includes a remote bulb and is suitable for installation in wells on boilers, storage tanks, and other pressurized vessels.

The L4006E series is engineered to break on temperature rise. Once the setpoint is exceeded, the manual reset must be engaged to restore system function, making it appropriate for limit-only protection circuits.

Key Functional Features

• Control Type: High limit with manual reset
• Switch Action: SPST opens on temperature rise
• Mounting: Horizontal or vertical immersion well installation (well sold separately)
• Sensor: Remote copper bulb – 3/8" diameter x 2-7/8" length
• Reset Method: Manual reset button located on control body

Technical Specifications

• Model: L4006E1067/U
• Temperature Range: 130°F to 270°F (adjustable setpoint)
• Differential: Fixed
• Electrical Rating: 5.1 to 48 A depending on load type and voltage
• Voltage: 120/240 VAC, 60 Hz
• Bulb Material: Copper
• Includes: Well adapter for remote bulb installation

Installation Requirements

This control is intended for use in closed-loop hydronic systems. Installation should be performed by licensed HVAC professionals. The remote sensing bulb must be fully inserted into a compatible immersion well with proper thermal contact. All wiring should comply with NEC and local electrical codes. Manual reset functionality is essential for applications requiring lockout after high limit activation.

Applications

• Boiler high-limit control with manual reset requirement
• Storage tank temperature safety cutoff
• Process fluid over-temperature shutdown in hydronic heating systems