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Lennox Pulse

Justasking Member Posts: 1
I have a Lennox Pulse which has worked well for 20 years. Now it doesn't respond to the thermostat's call for heat. I can switch the power off and on and then it will work okay for maybe a month. Is this a furnace issue or a thermostat issue?


  • AnthraciteEnergetics
    AnthraciteEnergetics Member Posts: 77
    edited November 2017
    Check the wiring, make sure it isnt loose or corroded. When it doesnt work try shorting together the red and white wires at thermostat see if it works. If it does, potential bad thermostat. Check batteries in thermostat, if any. Make sure exhausts/intakes are free of restrictions. Make sure gas pressure and electric power are ok. Any error lights/indicators on the unit that may be telling you something?
    EBEBRATT-Ed Member Posts: 11,985
    When was the last time you had it serviced??

    Although gas appliances are usually trouble free they should still be checked and serviced especially @20 years old furnace
  • Ironman
    Ironman Member Posts: 6,868
    The furnace is obsolete and Lennox is not offering parts anymore. They want the heat exchanger pressure tested since most all of them have failed. That costs a lot more than that old furnace is worth.

    If it's not something minor, you need to look at replacing it.

    Check the condensate drain lines and make sure ALL (inside and out) of them are clear.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • GW
    GW Member Posts: 4,536
    20 years; it's lived a good life. Time for a new one.
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    [email protected]
  • Henry
    Henry Member Posts: 995
    That and the "Complet Heat" were two Lennox disasters. Time to change for a HTP or Lochinvar!
  • Rich_L
    Rich_L Member Posts: 77
    If your condensate drain isn't clogged I'd bet money you need a new board. Those just don't last. The Pulse is tough to service and not a popular furnace amongst the pros... me included!
  • unclejohn
    unclejohn Member Posts: 1,757
    It is a very good furnace. Just that many of them were not installed properly. I have two in service 26 years. You are supposed to replace the check valves every five years I believe.
  • Henry
    Henry Member Posts: 995
    They lasted less than 10 years here with multiple issues!