if your system requires a pre-installed shutter

this device is engineered to monitor furnace plenum temperatures and interrupt the electrical circuit if internal heat exceeds its 255°F set point

a certified vent limiting device must be installed per local mechanical codes

It is critical to stay within the 145-174 microfarad range

Rheem-Ruud SP20166B Gas Valve Els PW 17895 if your system requires aThe Rheem Ruud SP20166B is a direct replacement natural gas valve engineered for 4" WC manifold pressure applications. Designed for high reliability in residential HVAC systems, this 1 2" NPT gas valve features a compact footprint and standard 1 2 inch inlet outlet ports, ensuring a straightforward fit during field replacements. As a critical component in the combustion string, the SP20166B manages fuel flow with precision, maintaining stable pressure