Honeywell VK4105A2025 gas valve

The Honeywell VK4105A2025U gas valve is part of the burner ignition control system and provides reliable ignition, flame control, and gas flow control for the pilot and main burners. This device contains a gas solenoid valve VK4105A 2025B and an ignition regulator that is connected to this valve.

The Honeywell VK4105A2025B combined gas valve has a standard housing and numerous settings, such as:

• Pressure control using a servo.
• Regulation using a throttle valve.
• Start with smooth ignition using innovative SOFTLITE technology.
• Regulation of the mixture of gas and air in a ratio of 1:1.
• Electric two-level control mechanism.
• Gradual adjustment with the possibility of adjustment for various control methods.

The Resideo VK4105 A 2025U gas regulator is equipped with two electrical devices:

1. device for precise control of the main valve;
2. device for constant monitoring of the valve position.

This regulator works with different types of gases:

1. heating
2. natural
3. liquefied

Standard operating conditions

• The medium maintains a temperature of 20°C.
• The diameter of the diaphragm is 2.8 millimeters.
• The Honeywell VK4105 A 2025B gas valve operates at rated voltage and is installed in an upright position for optimal performance.
• The gas inlet pressure is nominally 25 millibars with dry air and a stable temperature of 20°C.
• Gas consumption is measured in cubic meters per hour for maximum accuracy.
• The ambient pressure remains at 1013 millibars, ensuring reliable operating conditions.
• The output pressure is recorded using a sensor connected to a 1/2-inch pipe 10 times the diameter through a short hose with a length equal to 5 pipe diameters.

General features

The inlet and outlet of the VK4105 A 2025U gas solenoid valve have a diameter of 18.6 millimeters and are connected via flanges. There are different models of this gas valve with different levels of closing force, such as:

1. B + J
2. B + C
3. B + B.

At the inlet of the valve Honeywell VK4105A2025B there is a built-in fine-mesh filter, not intended for cleaning. If necessary, an additional output filter can be installed. At the bottom of the valve there are holes for mounting to the installation.

There are variants of gas regulators with a side outlet for the main and pilot burners. But such a side outlet can only be used with the flange collector of the burner. In addition, there is a connection for pilot gas with a diameter of 4 mm at the output of the VK4105A2025 regulator. It is also possible to install pressure measuring fittings using silicone tubes with a diameter of 4 or 6 mm.

There is a choice of different types of electrical connections, such as connecting to the ignition regulator via a connector or using a plug-in rectifier unit for standard DBI ignition systems. Options for operation at a voltage of 24V are also available for best compatibility with various ignition regulators, with the exception of the S4565/S4585 series regulators.

The principle of operation

VK4105A 2025 gas regulators have a positive feedback system (automatic closing of the main valve in case of lack of power supply or excess gas pressure). The system includes a high-tech pressure servo controller and a pressure relief valve that cooperate with each other. When the power supply is supplied, the gas passes through the servo controller and opens the main valve. The system then maintains a constant pressure by regulating the operation of the main valve. This ensures a stable output pressure, even with changes in the input pressure, and emphasizes its reliability in operation.