Honeywell, L7224U1002/U, Universal Electronic Oil Aquastat

Honeywell L7224U1002/U Universal Electronic Oil Aquastat Controller

The Honeywell L7224U1002/U is a universal electronic aquastat controller designed for use with oil-fired hydronic heating appliances. It provides electronic temperature sensing and high-limit control along with circulator and burner relay management, replacing a wide range of existing aquastats in both retrofit and new installations.

This controller supports a variety of mounting configurations and includes integrated diagnostics to aid in service and commissioning. It is compatible with systems using a 120 VAC power supply and operates across a broad temperature and differential range to accommodate a wide array of oil heating system requirements.

Functional Capabilities

• Electronic High-Limit and Circulator Control – Monitors boiler water temperature and activates burner or circulator based on setpoints.
• Universal Replacement – Supports applications requiring replacement of L8124, L8148, L7224 series controls, and others.
• EnviroCOM™ Communication Port – Allows integration with select advanced Honeywell system diagnostics tools.
• LED Indicators – Provides operational and fault status for service technicians.
• Multiple Mounting Options – Suitable for horizontal, vertical, or immersion well installation.

Technical Specifications

• Temperature Range: 130°F to 240°F
• Differential Range: 5°F to 20°F
• Operating Voltage: 120 VAC, 60 Hz
• Humidity: 0–95% RH (non-condensing)
• Controller Type: Aquastat for oil-fired heating systems

Installation Requirements

This controller is designed for use by HVAC professionals. Wiring must follow the system’s electrical schematic and adhere to applicable NEC and local codes. After installation, verify setpoints and test burner, circulator, and safety limit operation. It is not intended for gas-fired equipment or systems requiring low-water cutoff integration within the aquastat housing.

Contractor Notes

The L7224U1002/U simplifies service work by replacing over 40 Honeywell and competitor aquastats with a single configurable unit. It is especially suitable for oil systems requiring precise temperature control and diagnostic access via LED interface and communication port.