Lennox 10X87 Controller R 134A Utilizing genuine York service parts Utilizing genuine York service parts for terminal repairs preserves original equipment specifications and prevents the impedance issues often associated with generic aftermarket pigtails or spliced connections This dual state operation allows for flexible diverting relay applications The Lennox 10X87 C3 Controller is a high performance HVAC control board engineered for precision management of heating and cooling cycles in light commercial and residential Lennox Prodigy systems which is critical for technicians performing long term maintenance and troubleshooting on popular units like the LCH210H4 03 and LCH300S4 04 models