this component monitors high-side plenum temperatures to prevent thermal runaway and heat exchanger damage

the "/U" suffix simply denotes "Universal" packaging for retail or wholesale distribution

000 operations

achieving up to 10

transitioning to a 1/4" male flare (SAE) output

Lennox 31J91 LP Pilot Orifice this component monitors high-side plenumThe Lennox 31J91 LP Pilot Orifice is a precision engineered liquid propane (LP) conversion component designed specifically for residential and commercial gas heating systems. As a critical mechanical replacement for the legacy 31J9101, this red coded orifice ensures consistent gas flow regulation to the pilot burner assembly, maintaining a stable flame for reliable ignition cycles. Field tested for durability, the Lennox 31J91 is manufactured from