Reznor 103500 Transformer

For veteran technicians managing Reznor unit heaters, the Reznor 103500 Transformer provides the critical power conversion required for stable control circuit operation. This heavy-duty 208V to 24V HVAC transformer is specifically engineered to step down 208V primary line voltage to a reliable 24V secondary output. With a 40VA power rating, it delivers sufficient amperage to drive low-voltage components including thermostats, ignition modules, gas valves, and safety limit switches without the risk of voltage sag during peak demand. As a genuine Reznor replacement part, this transformer ensures precise physical and electrical compatibility with B, BE, F, and FE series units, eliminating the troubleshooting headaches associated with universal multi-tap alternatives. The robust internal windings are designed for high-cycle industrial environments, providing the thermal stability necessary to prevent inductive load failures in commercial heating systems.

• Precise Voltage Regulation: Consistent 208V primary to 24V secondary step-down for sensitive HVACR control boards.
• 40VA Capacity: High-amperage output supports simultaneous operation of multiple low-voltage controls and relays.
• OEM Engineering: Direct physical replacement for Reznor 103500, ensuring matched lead lengths and mounting footprints.
• Industrial Durability: Built to withstand the high ambient temperatures and vibration profiles common in rooftop and unit heater cabinets.

Can I use this for a 240V primary application?
This specific model is optimized for 208V primary lines. Using it on a 240V circuit may result in secondary voltages exceeding the standard 24V range, which could damage sensitive ignition modules or control boards.

How do I diagnose a failed control transformer?
Verify 208V across the primary leads. If primary power is present but you register 0V on the secondary side under no load, the internal thermal fuse or windings have likely opened due to a short circuit in the 24V field wiring.

Will this power a smart thermostat on an older Reznor unit?
The 40VA rating generally provides sufficient overhead for modern smart thermostats and Wi-Fi modules, provided the total secondary load does not exceed the volt-ampere limit.

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.