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  1. #1
    Join Date
    Jun 2007
    Posts
    820

    replacing a reversing valve.

    When you find a compressor that has grounded, the refrigerant has that nasty rotten egg smell because the refrigerant is now acidic, Why is it important to change out the reversing valve aswell, does the contaminated refrigerant do something to the reversing valve, by not replacing it will it damage the new compressor. I worked with someone that had this issue, he replaced the compressor and reversing valve, i asked him the same question and he told me that you just do. Can someone explain it to me, thx.

  2. #2
    Join Date
    May 2007
    Location
    San Francisco
    Posts
    258
    suppose a fault in the reversing valve contributed to the compressor failure. you may not be able to diagnose this until you've put the system completely back online. I think the feeling is that it is better to just replace it while you've got the circuit open, since it's essentially impossible to fully confirm proper reversing valve operation without the compressor running

  3. #3
    Join Date
    Feb 2005
    Location
    Honolulu
    Posts
    53

    How bad was the burnout?

    Although I have only worked on a dozen or so heat pumps with no burnouts yet. After more than 20 year in HVAC industry have heard lots of stories of reversing valves plugging up or sticking and contributing to compressor failure. In a case like that I can see a reversing valve needing to be changed with the compressor but after factoring in the valve, compressor and extra labor costs money-wise it would not be much different and often over all cheaper to replace the entire condensing unit.
    Another thing to consider is how far did the burnout spread? Although not on a H/P I have had a couple really bad A/C burnouts that have spread nasty black sludge throughout the system before the compressor quit pumping. If some of that sludge gets into the valve it could lead to valve sticking or plugging an orifice. That is why it is important to cut out a burnt compressor rather than un-soldering it.
    So its my opinion that if you have a compressor failure caused by a faulty reversing valve or had a reversing valve that is somehow damaged during a compressor burnout I would recommend changing the entire condensing unit. But if you have a burnout and feel that all the damage is limited to just the compressor only change the compressor (its a given that you would also change the filter drier, install suction drier and do your proper cleanup procedures). But do not change parts that you feel are not bad.

  4. #4
    Join Date
    Jul 2007
    Location
    East Haven,CT
    Posts
    159
    dont forget the txv

  5. #5
    Join Date
    Feb 2005
    Posts
    284
    dont forget the accumulator also

  6. #6
    Join Date
    Jul 2007
    Location
    Delta BC Canada
    Posts
    92

    Reversing Valve

    Having done my share of warranty work on heat pumps both air to air and water source I find most mfg's require you replace the reversing valve with the compressors .I have even had mfg's reps show up to check that both compressor and reversing valve was changed

  7. #7
    Join Date
    Feb 2006
    Location
    SouthEastern Virginia
    Posts
    1,076
    Don't forget this, don't forget that, Too much nickel and diming.Just replace the whole thing if you have to replace all the major components in it.

  8. #8
    Best To Replace Txv.

  9. #9
    Join Date
    Aug 2006
    Posts
    2,606
    Is this a water source heat pump, what size is it and how old is it? I've had plenty that had water leak into the refrigerant. They aren't worth fixing. Don't think that just because it has a charge in it there is no water leaking into the refrigerant circuit.

  10. #10
    Join Date
    Feb 2004
    Location
    New Mexico
    Posts
    5,593
    It's not the valve as such. It's the little tubes comming from the solinoid that can plug up from a burnout.
    And like was said, cut the valve out and braze new stubs with couplings to the new valve. Cutting out the valve is the fastest way no matter why you're changing it. It's a lot less trouble when you can do most of the brazing outside the unit.
    Tracers work both ways.

  11. #11
    Join Date
    Jun 2007
    Posts
    820
    The unit was a Carrier roof top package unit, air cooled coils. it looked no more than five years old. The compressor had windings that grounded to the compressor body, and the smell of the refrigerant was very obious that it was now acidic. The guy i helped out did all the work as far as brazing everything together, he replaced the reversing valve, added a liquid line filter drier, new compressor and that was it.

    About two weeks later, i was called out there again, the service mgr happened to be in the area, we both met at the store, and we found the compressor to be grounded again, with the refrigerant acidic again. Oh man was he pissed, he said that the journeyman should of known better, according to him the journeyman should of installed a suction filter drier, add a liquid line drier, replaced the reversing valve, replaced the accumalator aswell, poured some Acid Away in the new compressor, blown out the indoor/outdoor coil with nitrogen to get any oil out of there, do a deep vacuum, recharge, and schedule to come back to remove the suction drier.
    I never dared to ask anything further about what happened.

  12. #12
    Join Date
    Feb 2004
    Location
    New Mexico
    Posts
    5,593
    Allmost all compressor failures are external to the compressor.
    Changing all thet stuff there was still a good chance of a repeat failure.

    I had a failure with all the usual voltage protection, phase protection ect.
    The problem was a poor buss connection in another panel. The compressor was fed from a subpanel.

    If you don't find the correct failure mode the chances of another are huge. All that acid reducing efforts were treating a an effect not a cause.
    Tracers work both ways.

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