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Thread: Lennox problem

  1. #1

    Lennox problem

    Ran into a Lennox that has me pulling my hair out. 3 Ton package heat
    pump. It is approx 10 years old with no more than routine maintenance
    needed since installation ,until a couple of weeks ago. Condensing motor
    keeps going out on thermal overload. First call, it seemed that it was a
    bad defrost board. Replaced that, unit did o.k. for 3 days then, out again.
    Voltage is 235VAC. The compressor and indoor blower continue to run after
    cond. motor quits. To date I have replaced the board, the time delay,
    the 1/3 Hp 1075 (original) motor and cap. and have thoroughly cleaned the
    coils (twice). I baby sat it for over 3 hours. Unit will come on run between
    20 minutes and almost an hour but when outdoor temp gets above 90 degrees
    F. Motor will (Click) and opens on thermal again. This unit belongs to a friend
    therefore no money has changed hands at my suggestion until it works.
    According to Lennox, the original motor was not a high temperature motor so
    what gives with this. After 15 years in the business, I have never run into
    this problem in the past. Any suggestions would be greatly appreciated.
    Festus

  2. #2
    Join Date
    Feb 2008
    Location
    Western NC
    Posts
    2,504
    yeah

    change out everything that says Lennox!!!

    Sounds like a wiring issue. You say you've replaced different components, but are you sure you installed new components that are good??? I've seen plenty of motors bad outta the box. I've also seen plenty of defrost controls bad outta the box. Time to go back to sqare one.


    Also, apply for pro. We can't really help you here in open forum. So thats all I will say.
    I fully support the military and the War on Terrorism.


    If you don't know, then don't do. If you don't know and still do, then be prepared to pay someone else a lot to undo what you did and then do it right.

    If you do know, then do. But do it right. Otherwise, you may not be doing it long.

  3. #3
    Join Date
    May 2007
    Location
    DC Metro Area (MD)
    Posts
    3,368
    change out everything that says Lennox!!!
    Ah, no luck with Lennox for ya? I've heard their commercial L Series unit is nice at least.

  4. #4
    Join Date
    Dec 2002
    Location
    Toledo, Ohio, United States
    Posts
    12,901
    Twilli says have Ruthie yank it out
    No Heat No Cool You need Action Fast

  5. #5
    Join Date
    Feb 2008
    Location
    Western NC
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    2,504
    Quote Originally Posted by RyanHughes View Post
    Ah, no luck with Lennox for ya? I've heard their commercial L Series unit is nice at least.
    Luckily, I don't have to see too many Lennox units anymore. And the only ones I see are the newer commercial units. They are ok.

    If it weren't for bad luck, I'd have none at all. Have had 2 days off in the last 4 weeks. and spent both days cuttin grass. Go figure.
    I fully support the military and the War on Terrorism.


    If you don't know, then don't do. If you don't know and still do, then be prepared to pay someone else a lot to undo what you did and then do it right.

    If you do know, then do. But do it right. Otherwise, you may not be doing it long.

  6. #6
    Join Date
    May 2006
    Posts
    122
    I've had severley burnt breaker may cause this problem, if the unit has a hard start, the compressor would still start, if the unit was misswired, the only way it would run that long is if the run wire to the condenser motor is wired to the herm on the comp run cap. You could have the Wrong size run cap or a low run cap. Ive never had a Bad motor from lennox, A burnt defrost contacts in the control would do it, Hmm

  7. #7
    Thanks for reply to lennox fan problem. As of now I've tried 2 new defrost
    boards. They each do the same thing. On a call for cool the indoor blower,
    compressor, and condensing motor all start as expected. After a few minutes
    I can hear a "click" in the motor area and the cond. motor stops. The rest
    continues to run. I've tried 2 new combo caps (a 40/5) 370V and that makes
    no difference. The wiring checks ok to the cap. I've even tried just a single
    5mfd run cap and the same thing happens. One new motor was an A.O. Smith
    the other I tried is a G.E. 1/4 HP 1075 RPM. Both new motors did the same.
    Something (excessive heat from coil or compressor is shutting these motors
    down on thermal) What gives with this piece of crap???

  8. #8
    Thanks for reply to lennox fan problem. As of now I've tried 2 new defrost
    boards. They each do the same thing. On a call for cool the indoor blower,
    compressor, and condensing motor all start as expected. After a few minutes
    I can hear a "click" in the motor area and the cond. motor stops. The rest
    continues to run. I've tried 2 new combo caps (a 40/5) 370V and that makes
    no difference. The wiring checks ok to the cap. I've even tried just a single
    5mfd run cap and the same thing happens. One new motor was an A.O. Smith
    the other I tried is a G.E. 1/4 HP 1075 RPM. Both new motors did the same.
    Something (excessive heat from coil or compressor is shutting these motors
    down on thermal) What gives with this piece of crap???

  9. #9
    I will sign up for pro as soon as I get a few more posts under my belt,
    behind my back or over my head. Any help now is appreciated.

  10. #10
    Join Date
    Feb 2008
    Location
    Western NC
    Posts
    2,504
    Is the motor spinning the right direction????????
    I fully support the military and the War on Terrorism.


    If you don't know, then don't do. If you don't know and still do, then be prepared to pay someone else a lot to undo what you did and then do it right.

    If you do know, then do. But do it right. Otherwise, you may not be doing it long.

  11. #11
    Join Date
    Aug 2007
    Location
    MN
    Posts
    2,677
    Quote Originally Posted by RyanHughes View Post
    I've heard their commercial L Series unit is nice at least.
    they can keep em Gotta love the split condenser setup, 30 tons units have access doors to backflush the coils but the middle sections you have to crawl up top and remove the fan guards to hose them out. 10,000 relays, and all kinds of extra parts to diagnose. At least there is about 20 of everything to swap around if you get stumped
    You can't fix stupid

  12. #12
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,708
    Why are you putting on 1/4HP motors if the original was 1/3?

    Is the fan blade original, or was that replaced.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  13. #13
    Join Date
    Feb 2008
    Location
    Western NC
    Posts
    2,504
    Quote Originally Posted by cmajerus View Post
    they can keep em Gotta love the split condenser setup, 30 tons units have access doors to backflush the coils but the middle sections you have to crawl up top and remove the fan guards to hose them out. 10,000 relays, and all kinds of extra parts to diagnose. At least there is about 20 of everything to swap around if you get stumped
    don't forget the Lennox trademark. Every wire is the same freakin color. With tiny little numbers at each end. Good luck tracing.
    I fully support the military and the War on Terrorism.


    If you don't know, then don't do. If you don't know and still do, then be prepared to pay someone else a lot to undo what you did and then do it right.

    If you do know, then do. But do it right. Otherwise, you may not be doing it long.

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