Weil McLain 383-500-628 Transformer

The Weil McLain 383-500-628 Transformer is a heavy-duty, factory-specified 120V to 24V step-down transformer designed for critical power distribution within high-efficiency hydronic systems. This 50VA boiler transformer provides a stable 24VAC secondary output, ensuring consistent low-voltage signaling for the Weil McLain Ultra boiler control board and ignition sequences. As a direct replacement for the legacy 511-802-011, it is engineered to handle the electrical load requirements of Weil McLain Ultra Gas and Ultra Commercial models (sizes 550 and 750). The high-amperage capacity prevents control voltage drops during simultaneous component activation, such as gas valve solenoids and inducer relays. Built for the high-temperature environments of professional mechanical rooms, this OEM Weil McLain electrical part ensures precise 120V primary isolation and is essential for maintaining the operational integrity of commercial heating equipment. Precise terminal termination and iron-core efficiency make it the standard choice for service technicians performing hydronic heating system repair.

Key Benefits

• OEM Compatibility: Specifically engineered as the direct replacement for Ultra Series Gas and Commercial boilers.
• High Power Capacity: Rated at 50VA to support complex control circuits and multiple low-voltage accessories without overheating.
• Reliable Voltage Conversion: Accurately steps down 120V line voltage to a steady 24V output to protect sensitive logic modules.
• Simplified Integration: Standardized mounting footprint and terminal layout reduce downtime during field replacements.

Common Questions

Can the 383-500-628 replace the older 511-802-011 model?
Yes, this part is the official factory-designated replacement for the 511-802-011 and meets all original electrical specifications for the Ultra series.

Is this transformer compatible with other boiler brands?
While it provides a standard 120V/24V 50VA output, it is specifically configured for Weil McLain mounting brackets and harness connections found in the Ultra series. Field-fitting in other brands is not recommended.

How do I verify if the 50VA rating is sufficient for my system?
The 50VA rating is optimized for the factory control configurations of the Ultra 550 and 750 models. If you have added significant external zone valves or heavy secondary loads, verify total VA draw before installation.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.