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Old furnace

leaking Member Posts: 46
I have a 15 year old Lennox furnace that doesn’t work and can’t afford a new one. It didn’t run last winter Chicago we used electric heaters . I had no co issues when it ran so the heat exchanger is ok.

I had out 4 repair people, one was a relative that couldn’t get it running, one said he replaced the control board. I don’t know if it was a new replacement or even done right. All are trying to sell me a new unit I can’t afford and they say they don’t know what’s wrong.

Did I get 4 dumb repairman - salesman, or are there furnaces that can not be fixed? From what I’ve tried to learn this is actually fairly simple , a few main parts, and that unless the heat exchanger leaks then it’s fixable !

Should I try to get another real professional to repair it or give up and go borrow money?
I think it could be something simple like a broken wire or something they all missed .

I took off the thermostat to replace it and after all the repair men I found the red wire was not even tightened in the thermostat it was loose. I couldn’t figure out if it was wired right and it didn’t turn on. Cold in Chicago , house big family of 7 electric bill is killing us . I don’t even know what’s wrong with it. Nobody said what’s wrong. Thanks for advice.


  • clammy
    clammy Member Posts: 3,113
    At 15 years old that unit should have a diagnose code which should help in trouble shooting which usually consists of some flashing led lights which will help pin point the issue . At 15 years old a competent service person should be able to get a handle on it . Personally I would remove the access door from the unit ,being sure to keep the blower door safety engaged ,disconnect the low voltage wiring from its terminal board and jump the low voltage terminals first r to g to ensure that the blower motor is functional then remove and jump the r to w if the inducer blower should start followed by the hot surface ignitor then the gas valve should open and flame be lite and the limit should shortly start the blower motor . Personally you need to find a real service tech that does Hvac and not a franchise business, not a plumber ,most plumber are not really familiar w hot air furnaces and the sequence of operation,If your still having a hard time find your self a Lennox dealer and have then take a look . Personally I ve seen a lot of larger companies ( flat rates purchased chain franchises ) pushing replacement of every furnace they see saying a 11 year old furnace is shot even when they recommended ,installed and received payment to perform preventive maintenance over the years and now when things are a little tough they recommend replacement of anything and tell the perils of price increases on equiptment all for another install sale instead of really honest service . In my book after 20 years most newer hot air furnaces are usually done being there built for the landfill and most are throw always . But calling 4 seperate heating contractors and none can repair or find the issue sounds like they all stink at there jobs . If they don’t have a electric meter for starters dont even bother to let them in the door ,nothing electrical gets checked without one and if they don’t have one there the wrong service guy . Has any one also checked your gas service and gas pressure if there’s no gas ( meter being shut off ) there’s no heat . In closing you need to find a real service guy not the cheapest guy locale to you usually there’s a reason there cheap . And if they have done nothing then it should cost nothing or at least not be a absorbingly high bill being there was no results meaning still no heat . On a side was the unit properly installed following installation instructions , at 15 years a improperly installed furnace would most like be done due to a variety of improperly done things like undersized return ducting ,improper gas sizing ,under sized supply ducting ,improperly venting to chimney some of which will cause burner short cycling and shorting component life span . Peace and good luck clammy
    Peace and good luck clammy
    R.A. Calmbacher L.L.C. HVAC
    NJ Master HVAC Lic.
    Mahwah, NJ
    Specializing in steam and hydronic heating