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  1. #1
    Join Date
    Jun 2019
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    reversing valve?

    I went to do annual maintenance on a split heat pump R22 system

    At first- little issues- bad compressor cap- measures 20mf vs 40- changed- everything seems ok. I change severely pitted/burned contactor- so it should be good to go. I go to check pressures-. The vapor line was HOT- like super hot. My thermometers clamped to both liquid and vapor measured about 150-160. The liquid line was cooler slightly. Also the vapor pressure was 300 and the liquid was 250-260. I am assuming its stuck in heat and vapor line was very hot. Far hotter than normal heat pump output.

    I checked the coil on reversing valve- 15ohms, and 24 v present. The reversing valve is discolored obviously due to heat. The customer said "last summer when we used it last for cooling- it seemed to take the house a long time to cool off"---

    What is strange is that everything is hot,,very hot. both pressures are high. At first I thought the reversing valve was stuck - but now I am wondering if the compressor valves are leaking. My understanding is that if the valves in the compressor are bad- the high side would be normal or low- and low would be high. What if both the reversing valve is bad or stuck and it damaged the compressor valves from heat. This is really hot. 150-160 degrees on both thermometers. If it were stuck in heat (working properly) - the liquid line would be cool- and so would the condenser coils---its all hot.

    I have never seen this. I dont want to change the reversing valve just to find out the compressor is bad- and surely am not comfy changing compressor without being 100% certain it needs to be changed.

    Ideas? I know a bad reversing valve can cause high pressures. I am confused by everything being hot- comments/ideas? I need to go do more checking- it just got so hot yesterday the compressor shut down so I called it quits until it cooled off.

  2. #2
    Join Date
    Jul 2013
    Location
    Richmond, VA
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    First off, what brand unit is this?

  3. #3
    Join Date
    Jan 2014
    Location
    New England
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    Recipercating compressor? If so pump it down, as low as it will go, without going in a vacumn, ( depending on refrigerant charge and capacity of OD coil ) to see if low pressure does not climb quickly once you shut off compressor.

    It may rise slowly a little as there still may be a little vapor left. You would need to make sure RV coil does not drop out. It needs to be energized. Then shut off compressor, at the disconnect switch ( RV coil should still be energized from stat, talking a system where RV coil energizes in cool mode ) see what happens.

    Energize and deenergize RV coil to hear the clicking sound with compressor off, try running unit compressor and energy/deenergize RV every few seconds to hear it shift. Change out RV coil with a good used one as another check.

    How old is this system, maybe it’s time to give up the ghost if the Heat Pump is old and high mileage.

    What was the amprege draw compared to the FLA. What was the common suction pressure reading, you gave the LL and what sounds like the discharge line ( vapor line ) but left out the dedicated suction Schrader.

    “ I have never seen this. I dont want to change the reversing valve just to find out the compressor is bad- and surely am not comfy changing compressor without being 100% certain it needs to be changed.”

    Some companies change them both at the same time, figure it doesn’t make them look to bad in front of customers...

    Try running in heat mode to see if vapor line gets relatively hot then manually energies RV coil to see if it switches OK and starts cooling down. ( talking RV models that energies in cool )
    Last edited by Bazooka Joey; 04-04-2020 at 06:20 PM.

  4. #4
    Join Date
    Jun 2019
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    Thread Starter
    its a goodman---and yes- recip compressor. I was going to pump it down today- but it gets so incredibly hot. Its 11 yrs old and its in phoenix so yes- its got a lot of miles. I will do a little more testing and see what it brings. Thanks for your help- I will let you know what happens. I think I have a coil ---I scavenged one off a unit getting scrapped- so I can try that- I didn't think to do that---good idea.

  5. #5
    Join Date
    Jan 2014
    Location
    New England
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    Quote Originally Posted by mtsaz100 View Post
    its a goodman---and yes- recip compressor. I was going to pump it down today- but it gets so incredibly hot. Its 11 yrs old and its in phoenix so yes- its got a lot of miles. I will do a little more testing and see what it brings. Thanks for your help- I will let you know what happens. I think I have a coil ---I scavenged one off a unit getting scrapped- so I can try that- I didn't think to do that---good idea.
    300 PSI for R22 is not terribly high, figure around 225-260+ and the suction 65-75+. Give or take. With a good load.

    Don’t you have a dedicated suction Schrader port between the two service valves? That’s where you should be checking for one reading. You can hook one wire of the coil to C and use jumper wire from R to other wire of coil to manually energies/deenergize the coil. Making sure you have good 24v out there by unit. This way you have control.

    The spare RV coil orifice does not have to be a exact fit on the RV shaft, as using a screwdriver that’s has a loose fit works OK.

    You got access to a garden hose to keep OD unit cool, while troubleshooting?
    Last edited by Bazooka Joey; 04-04-2020 at 07:28 PM.

  6. #6
    Join Date
    Jan 2004
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    PA
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    Takes a while for a compressor that is not pumping to hat up. So if its getting hot quickly, its the RV.
    Contractor locator map

    How-to-apply-for-Professional

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

  7. #7
    Join Date
    Sep 2002
    Location
    Virginia
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    if they have the money , install a new system

    If its been runnin hot for a while , its not going to be dependable anymore

    Might even have acid running through it by now , and that stuff slowly eats the windings

  8. Likes Bazooka Joey liked this post.
  9. #8
    Join Date
    Jun 2019
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    Thread Starter
    [QUOTE=Snapperhead;25850659]if they have the money , install a new system

    If its been runnin hot for a while , its not going to be dependable anymore

    Might even have acid running through it by now , and that stuff slowly eats the windings[/QUO


    I priced a new condenser- I wasnt concerned so much about the pressures as the temps. 160+ on vapor and liquid line. anyway it was the reversing valve. It had been changed before. I use heat gel and wet rags---I suspect this was not done before or there was some debris (from valve failing before)-and the person who changed it before did not change filter (or they didn't do it right) but I suspect this is why it failed again. The reversing valve comes with a new filter for a reason. Working perfect now. I highly recommended they replace at least condenser- they wanted it fixed. I told them to prepare to replace system in coming months/year---and they said that they would.

    with this corona virus and people unsure about jobs- I can understand why they might want to save a dollar now even if it costs 2$ in future. It will be 100+ in the next few weeks- and corona or not- people will want their AC working.

    Thanks for your help everyone.

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