Velocity Boiler Works (Crown) 3502600 Transformer

The Velocity Boiler Works 3502600 Transformer is a critical electrical component designed for high-performance residential and commercial hydronic applications, providing a reliable 24V secondary output from a 115V primary supply. Engineered for compatibility with the Crown Boiler BWC120 and other heavy-duty heating systems, this 50VA control transformer offers the necessary power to handle complex control circuits, including those with multiple relays, zone valves, and smart thermostats that require consistent current without overheating.

For technicians in the field, this HVAC step-down transformer is a direct replacement for Velocity Boiler part number 3502600 (often cross-referenced as AT250A). Its 50VA rating provides approximately 2 Amps of current, offering more overhead than standard 40VA units to prevent brittleness in windings and voltage drops during peak demand. This unit ensures isolation between your line voltage and the sensitive 24V HVAC control circuit, protecting advanced ignition modules and sensors from electrical noise.

Key Benefits:

• High Capacity Output: The 50VA power rating supports expanded control loads, such as zone controllers and electronic dampers, reducing the risk of transformer burnout.
• Precision Voltage Conversion: Efficiently steps down 115v primary to 24v secondary for stable operation of Velocity Boiler Works components.
• Direct OEM Fit: Specifically engineered for the Crown BWC120 series, ensuring mounting holes and lead lengths align with the original factory specifications.
• Thermal Stability: Heavy-duty construction limits temperature rise during continuous duty, preventing internal short circuits on the secondary side.

Common Questions:

Can I use a 40VA transformer to replace this 50VA unit?
Using a lower VA rating is not recommended. If the control circuit—including the 24V gas valve and zone relays—exceeds a 40VA draw, the transformer will overheat and eventually fail. Always match or exceed the original VA rating for equipment stability.

How do I verify if the transformer is faulty during a service call?
Check for 115V at the primary leads. If input voltage is present but there is no 24V supply across the secondary terminals (or between R and C at the control board), the transformer has likely open-circuited. Also, check for the 1.6A slow-blow fuse often found inline on Velocity systems before replacing the transformer.

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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.