Weil McLain 640-000-043 Kit-S Outdoor Sensor Wall Mount

Description

The Weil McLain 640-000-043 is a factory-engineered outdoor temperature sensor kit designed for wall-mount installation on Weil McLain boiler and hydronic heating systems. By accurately measuring outdoor ambient temperature, this sensor enables outdoor reset control strategies that optimize boiler water temperature relative to outdoor conditions — improving system efficiency, comfort, and fuel savings.

Key Features

• Designed and engineered specifically for Weil McLain boiler systems
• Wall-mount (WMnt) configuration for exterior building installation
• Enables outdoor reset control for improved heating efficiency
• Provides accurate ambient temperature readings to the boiler control
• Direct OEM replacement for compatible Weil McLain models
• Durable construction suited for outdoor environmental exposure

Application

This outdoor sensor kit integrates with Weil McLain boiler controls to support outdoor air reset (OAR) functionality. When the control receives real-time outdoor temperature data, it can modulate boiler supply water temperature accordingly — reducing short cycling, lowering fuel consumption, and maintaining consistent indoor comfort across varying weather conditions.

Why Choose OEM Weil McLain Parts?

Using genuine Weil McLain replacement components ensures compatibility, maintains system warranty integrity, and delivers the reliable performance your hydronic system demands. The 640-000-043 is the correct factory-specified sensor for applicable Weil McLain boiler models.