Four Seasons 74925 HVAC Heater Control Valve

Four Seasons 74925 Heater Valve Overview

The Four Seasons 74925 is a rotary electronic heater valve built for HVAC temperature control in select Mercedes-Benz applications with an auxiliary heater. It uses an electric bypass-valve design and a plastic housing to regulate coolant flow through the heater circuit for consistent cabin heat control.

Four Seasons Heater Valve parts are backed by more than 50 years of mobile A/C experience and are engineered and tested for dependable operation. This Four Seasons 74925 heater control valve is a direct-fit style replacement for vehicles that require the specified connector layout and opening dimensions.

Key Features

• Rotary electronic heater valve for HVAC temperature control
• Electric bypass valve operation
• Plastic construction
• 5 connectors with 2 terminal pins
• Opening dimensions: 0.73 in, 0.74 in, 0.78 in, and 0.67 in, depending on port
• Cross-reference part numbers include Gates EHV138 and Genuine 2118320684

Product Details

This HVAC heater control valve is designed for Mercedes-Benz E320, E350, E500, E550, E55 AMG, and E63 AMG models equipped with an auxiliary heater. The Four Seasons 74925 part number is used in temperature control systems where coolant bypass routing must be managed electronically to maintain proper heater performance. If you are replacing a Mercedes-Benz E320 heater valve or sourcing a Mercedes-Benz E350 auxiliary heater valve, verify connector count, port size, and valve style against the original component before installation.

Compatible vehicle coverage includes 2003-2009 Mercedes-Benz E320, 2006-2009 Mercedes-Benz E350, 2007-2009 Mercedes-Benz E550, 2007-2009 Mercedes-Benz E63 AMG, 2003-2006 Mercedes-Benz E500, and 2004-2006 Mercedes-Benz E55 AMG, all noted for auxiliary heater use. The Four Seasons 74925 is also referenced by Anchor 300034, Gates EHV138, Genuine 2118320684, and H78014 for the same application.

Common Problems This Part Can Address

• Inconsistent cabin heat output
• Heater circuit coolant flow that does not respond correctly to HVAC commands
• Auxiliary heater temperature control faults
• Valve leakage or sticking in the heater circuit
• Electrical control issues at the heater valve connector

Installation Notes and Tips

• Confirm the vehicle is equipped with an auxiliary heater before ordering.
• Match the original connector count, terminal pin count, and port dimensions to the removed valve.
• Inspect coolant hoses and electrical connectors for wear before installing the replacement valve.
• After installation, refill and bleed the cooling system according to Mercedes-Benz service procedures.

Quality Assurance

Four Seasons engineers and tests its HVAC components for long service life and consistent operation. The 74925 heater valve reflects the brand’s mobile A/C and temperature-control experience, with a focus on accurate fit and reliable performance in the specified Mercedes-Benz applications.