Lennox 47K20 Transformer The York S1-9951-0931 is a

The York S1-9951-0931 is a precision-engineered LP Gas Orifice designed for specific burner manifold applications in York

the blower failing to engage during a call for heat

For contractors servicing Williams Monterey furnaces

If your diagnostics reveal furnace short cycling or 4-flash error codes

it maintains strict capacitance tolerances and high insulation resistance to prevent premature failure during frequent cycling

Lennox 47K20 Transformer The York S1-9951-0931 is aThe Lennox 47K20 Transformer is a heavy duty step down control transformer engineered for high demand HVAC low voltage control circuits. Designed to provide a reliable 24V secondary output from a 208 240V primary input, this 40VA Class 2 transformer ensures consistent power delivery to contactors, relays, and integrated furnace control boards. This unit is a direct OEM replacement part and is technically identical to the Lennox 47K2001 and the