OEM Lennox Pressure Switch — 26W83

The genuine OEM Lennox 26W83 pressure switch is the draft-proving safety control in your Lennox furnace, confirming that the inducer is pulling proper venting before ignition is allowed. It senses the pressure differential created by the draft inducer and closes its contacts only when airflow is adequate, giving the control board the green light to open the gas valve.

Signs of a failing 26W83 include a furnace that cycles the inducer without firing, a burner that lights and then quickly drops out, or a persistent pressure-switch lockout on the control board. Typical causes are a stuck or ruptured diaphragm, obstructed sensing tubing, condensate collecting in the port, or contacts that no longer make a reliable connection.

Because each Lennox pressure switch is calibrated to a specific set point for its inducer and venting arrangement, fitting the correct OEM part is essential. A mismatched aftermarket switch can allow combustion under unsafe draft or cause false lockouts that leave you without heat. The factory 26W83 provides the exact trip pressure Lennox designed, safeguards your warranty, and keeps this vital safety circuit performing as intended.