Lennox 10P17 Transformer

The Lennox 10P17 is a heavy-duty 40VA HVAC transformer engineered for multi-tap versatility in light commercial and residential climate control systems. Built to handle 120/208/240V primary inputs and provide a stable 24V secondary output, this replacement part ensures consistent power delivery to contactors, thermostats, and integrated furnace controls. This foot-mounted unit is essential for technicians addressing voltage drop issues or failing control circuits in Lennox and Allied Air equipment. The multi-voltage primary connections allow for broad application across different service environments, effectively replacing several single-tap models to reduce truck stock. With its robust winding construction and thermal protection, the 10P17 maintains high efficiency and reliable volt-ampere ratings under continuous load, mitigating the risk of control board failure due to inconsistent amperage. Use this direct replacement transformer to restore exact OEM specifications to the low-voltage control loop.

• Universal Primary Taps: Accommodates 120V, 208V, and 240V inputs for maximum site flexibility.
• 40VA Power Rating: Provides ample current for modern electronic controls and multiple 24V accessories.
• OEM Compatibility: Precision-fit for Lennox furnace parts and air handler control circuits.
• Foot Mount Design: Standard mounting footprint for fast mechanical installation in existing control panels.
• Durable Construction: High-grade laminations and encapsulated windings resist vibration and heat-cycling.

Commonly Asked Questions:

Can I use this to replace a 30VA transformer?
Yes, upgrading to a 40VA transformer provides a higher current ceiling, which is often beneficial if you have added external accessories like power-hungry smart thermostats or zone controllers, provided the secondary voltage matches.

How do I identify the common wire on the primary side?
Refer to the wiring diagram on the Lennox 10P17 housing. Typically, the white wire serves as the common for all primary voltages, but always verify with a multimeter during installation to ensure proper 24V output.

What causes these transformers to fail prematurely?
The most common causes are a short in the 24V contactor coil or a grounded thermostat wire. Always inspect the low-voltage circuit for shorts before installing the new 10P17 to prevent immediate damage.

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.