Lennox 26W86 2-Stage Dual Pressure Switch 0.9-1.2" WC

The Lennox 26W86 is a 2-stage pressure switch that works only with Lennox brand HVAC systems. It is used as a safety and efficiency control that measures pressure within the system. If pressure is less than a certain pressure of 0.9” WC, the switch turns on the furnace to heat. On the other hand, when it gets to a higher pressure of 1.2” WC, it triggers a shutdown of the furnace to prevent pressure that is dangerous to the system. This 2-stage operation makes sure that comfort is realized while at the same time eradicating the problem of over heating.