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  1. #1
    Join Date
    Nov 2019
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    Confused HP runs in cool but cuts out on High head in heat

    Hey guys I’m working on a 1996 Lennox. Unit cools great in summer, winter time came around and it went off in high head. I thought maybe it was the fan not ramping up to speed, check the amp draw it was good, blower wheel was dirty, cleaned it, Evap. Coil gets warm. You can hear the reversing valve engage and dis engage. Could it be the bi-flow? I kick myself for not taking temp on both sides of the drier. Any suggestions?

  2. #2
    Join Date
    Aug 2002
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    Southold, NY
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    If the blower wheel was dirty how was the amperage good?

    Super heat
    Sub Cooling #'s

    When was the last time this system was serviced?

  3. #3
    Join Date
    Nov 2008
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    Piney Flats, Tn.
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    Quote Originally Posted by pecmsg View Post
    If the blower wheel was dirty how was the amperage good?

    Super heat
    Sub Cooling #'s

    When was the last time this system was serviced?
    In the heat mode? I did not know you could charge with those #'s in the heat mode. And to me they do not mean much in the winter, I know I will get bashed for this but I go off of pressures for winter. Usually the manufacturer can tell you what it should be if you give them the proper information. You won't be right on those numbers but they can get you close.

  4. #4
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    Quote Originally Posted by DOGBOY View Post
    In the heat mode? I did not know you could charge with those #'s in the heat mode. And to me they do not mean much in the winter, I know I will get bashed for this but I go off of pressures for winter. Usually the manufacturer can tell you what it should be if you give them the proper information. You won't be right on those numbers but they can get you close.
    Its more to find out what the OP knows!

  5. #5
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    Nov 2019
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    Thread Starter
    Was there briefly did not take the time to get SH & SC. Cleaned the wheel before amping sorry put that in reverse order. The summer time pressures where great 60/215 winter time the high side runs for about 15 sec and the head pressure jumps strait up.

  6. #6
    Join Date
    Sep 2002
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    Let's think about this is very basic terms.

    For "heat pump" (reverse cycle) operation the outdoor coil is the evaporator and the indoor coil is the condenser.

    If you pretend that this job is cooling-only and you had the same symptoms - what would you think about checking? What could cause the symptom of excess head pressure be? And why?

    PHM
    --------



    Quote Originally Posted by Woodyard View Post
    . . . The summer time pressures where great 60/215 winter time the high side runs for about 15 sec and the head pressure jumps strait up.
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  7. #7
    Join Date
    Jan 2014
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    New England
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    Split system HP? if so is this a matched system, both ID and OD are the same tonnage and brand and SEER? Indoor evaporator, err condenser coil clean ( heat mode ) OD metering device metering?

    Why where you there in the summer as you mentioned it cools great? A basic PM check? Or Refrigerant charge adjustment/troubleshooting?
    Last edited by Bazooka Joey; 12-01-2019 at 03:39 PM.

  8. #8
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    Nov 2008
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    Piney Flats, Tn.
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    Quote Originally Posted by pecmsg View Post
    Its more to find out what the OP knows!
    I got it sorry.

    woodyard - when you say pressures are GREAT at 60 & 215 you should tells us at what indoor and outdoor temps and your sh & sc as lennox ALWAYS used txv's on their higher efficient equipment. I know these numbers were summer numbers but the sc tells us ALOT. I am sure most of us knows what the problem is but can not say in an open forum for what you should be doing to find out.

  9. #9
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    Nov 2019
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    Thread Starter
    Yes to the matched system question & The unit was down for a few years and found out it was due to the high head pressure switch tripped. I assumed a dirty filter knocked it out, because the filter was blacked out. I replaced it before turning the system back on.

  10. #10
    Join Date
    Nov 2006
    Location
    Athens, Ohio
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    AOP is the wrong forum. You need to click on the little black triangle at the bottom of your post and ask the moderator to move it to Tech to Tech forum.
    Provide your credentials as a technician.
    AOP Rules: Rules For Equipment Owners.

    Free online load calculator: http://www.loadcalc.net/


    There = not here. Their = possessive pronoun. They're = they are
    It's = contraction of it is. Its = the possessive form of it
    Too = also. To = expressing motion. Two = 2
    Then = after that, next. Than = indicates a comparison.
    Questions should end with a question mark "?" Statements end with a period "."

  11. #11
    Join Date
    Sep 2007
    Location
    State College, PA
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    Need more info, like indoor & outdoor temps.

    But the real issue is that we cannot give technical advice in an open forum. You need to get your post count up and ally for pro membership.
    Can someone please explain to me -
    Why is there never enough time to do it right the first time, but plenty of time to do it twice?


    Please view site rules: http://hvac-talk.com/vbb/showthread.php?t=1241

    Apply for Pro Membership: http://hvac-talk.com/vbb/showthread.php?t=116113

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  12. #12
    Join Date
    Mar 2018
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    Quote Originally Posted by Woodyard View Post
    Was there briefly did not take the time to get SH & SC. Cleaned the wheel before amping sorry put that in reverse order. The summer time pressures where great 60/215 winter time the high side runs for about 15 sec and the head pressure jumps strait up.
    This is not the first time I've heard 60 as "good" pressure for R22 in cooling on this forum. Really??? Also I agree with you DOGBOY. Mfg suggested pressures for conditions should be the first thing to compare to in heating mode.

  13. #13
    Join Date
    Sep 2002
    Location
    Virginia
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    Well lessseeee here

    Blower wheel was dirty , so the evap probly was too , and during a summer check someone added freeezy juice to bring up the low side

    Now winter is here and the thing is overcharged

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