Lennox 10P17 Transformer you would typically require the

you would typically require the 143-08-021-02 green spring

preventing the safety hazards associated with generic aftermarket alternatives

Whether used for low-ambient control or limit protection

If the switch opens before the 220°F threshold or remains open after the unit has cooled significantly

the furnace will drop the flame signal or lockout entirely

Lennox 10P17 Transformer you would typically require theThe 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