Honeywell L404F1391U Pressure Controller

Product Description

The Honeywell L404F1391U is a pressure controller designed to monitor and regulate system pressure in hydronic heating and cooling applications. It operates as a sensing and switching device that responds to changes in water or fluid pressure, opening or closing a circuit to protect equipment and maintain safe operating conditions. Licensed HVAC technicians and hydronic heating specialists typically install this controller as part of a boiler or circulating loop system. The L404F1391U provides reliable pressure-actuated switching to support both safety shutoff and operational control functions within closed-loop fluid systems.

This pressure controller is suited for residential and light commercial hydronic systems, including hot water boilers and associated piping loops. It is typically installed at a point in the system where pressure monitoring is required to trigger a control action, such as high-pressure cutout or low-pressure lockout. Consult the system schematic and original equipment documentation to confirm proper placement and setpoint configuration before installation.

Key Features

• Pressure-actuated switching for hydronic heating and cooling system control
• Supports both safety shutoff and operational pressure control functions
• Designed for installation in boiler and closed-loop fluid piping systems
• Compact controller format suitable for residential and light commercial applications

Compatibility

Designed as an OEM-style replacement pressure controller for residential and light commercial hydronic boiler and fluid system applications.

Installation Notes

Installation should be performed by a licensed HVAC technician or hydronic heating specialist familiar with applicable mechanical codes. Shut down the boiler and relieve system pressure before disconnecting or installing any pressure controller. Verify that system pressure is within the controller operating range before returning the system to service. Follow local codes and the equipment manufacturer's wiring and mounting instructions throughout the installation process.

Technical Specifications

• Weight: 2 pounds
• UPC: 08526725823

Standard Information

• Brand: Honeywell
• Manufacturer Part Number: L404F1391U