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Lennox Furnace Stopped Working.


I have a Lennox Elite Series Furnace model GHR26 that just completely stopped working on me last night.

The led's are flashing as follows

Led 1 is off

Led 2 is slowly flashing

I've tried looking for an obstruction in the inlet/exhaust vent.....nothing..

I've released water from the condensation trap, I've taken all the small tubes off the pressure switch itself to make sure they weren't obstructed and I still have no furnace working(it doesnt start at all just a couple of clicking noises)

My next guess would be to replace the pressure switch itself, but before I do that how do I go about diagnosing the switch as being bad??? Ive checked for voltage and the blue wire shows about 28vac and the other one(purple wire) shows about 2vac throughout the sequence of events the furnace runs through.  Any help would be greatly appreciated. 


  • Tim McElwain
    Tim McElwain Member Posts: 4,482
    What is the

    make and number of the board with the lights flashing? I need that so I can diagnose the flashing light.

    If I remember light 2 slow flashing it is a problem with the pressure switch, or a blocked inlet/exhaust vent, or the condensate line is plugged. Or it could be that the pressure switch stuck closed after the last call for heat ended.

    Check all your hoses and connections for moisture. Make sure no ice or snow is blocking your air for combustion.
  • Tim McElwain
    Tim McElwain Member Posts: 4,482
    Which model of

    Lennox GHR26 do you have? Is it mounted horizontally or is the blower above the burner (downflow)? Is the furnace a before 1997 or after?
  • Steve Whitbeck
    Steve Whitbeck Member Posts: 669

    Check for blockage inside the port where the pressure switch hoses connect. ( the red hose )
This discussion has been closed.