Lennox 17J42 Air Housing Kit

The Lennox 17J42 Air Housing Kit is an essential accessory meant only for Lennox brand of gas furnaces. It has a 2-stage pressure switch, which is a crucial task in the effective and safe working of a furnace. This switch measures the pressure of the air in the flue, the pipe that expels the combustion products out of your house. The two-stage pressure switch works as a safety switch in the system. When flue pressure drops below a safe minimum level, the switch causes the furnace to shut down to avert dangerous exhaust gases from building up inside