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  1. #27
    Join Date
    Jun 2008
    Location
    NW Florida
    Posts
    707

    Noise

    You will get a little extra noise with the piston in there along with the x-valve. (found that out the hard way) It will affect capacity and superheat. The x-valve must also have the superheat adjusted. Goodman and Amana use the same x-valve for 2 differant sizes it must be adjusted for the application.

    Rheem: I was told by the factory rep to take the pistons out and throw them away. They would cause a rattle and possible a whistle after unit sat off cycle for awhile.

  2. #28
    Join Date
    Apr 2007
    Posts
    623
    Ya mean ya dont need both, Also guys make a note, when installing a new condenser dont just sit it on top of the old condenser and tee the lines together

  3. #29
    Join Date
    Jul 2008
    Location
    Coastal North Carolina
    Posts
    10

    Smile

    Stopped up pistons act like misfeeding txv's, low suction, high superheat, high subcooling. Sometimes you have to break out something others than your guages and temp meter!

  4. #30
    Join Date
    Jan 2007
    Location
    N.E. Ok.
    Posts
    1,370
    A local Rheem dealer played a HO supplied tape recording which sounded like a thumping or chattering noise, thats what they said was the problem. idk



    Quote Originally Posted by meoberry View Post
    You will get a little extra noise with the piston in there along with the x-valve. (found that out the hard way) It will affect capacity and superheat. The x-valve must also have the superheat adjusted. Goodman and Amana use the same x-valve for 2 differant sizes it must be adjusted for the application.

    Rheem: I was told by the factory rep to take the pistons out and throw them away. They would cause a rattle and possible a whistle after unit sat off cycle for awhile.

  5. #31
    Join Date
    May 2006
    Posts
    281
    Quote Originally Posted by RoBoTeq View Post
    I've often wondered about this scenario. Rheem/Ruud uses, or at least used to, an over bored piston in conjunction with a TXV on their flex coils. We were told this was to more evenly distribute the TXV metered refrigerant to the distribution tubes.

    Since Goodman coils used on systems that are higher then 13 SEER are designed for higher capacity 13 SEER systems, they therefore have oversized pistons for the higher capacity systems. For example, this 3 ton system is using a coil that has a piston that is designed for use with a 5 ton (13 SEER) system.

    Since the piston is so oversized for the 3 ton system, will it really have any adverse affect being in the system after a TXV?

    Robo,
    You and Beenthere are correct, Rheem/Rudd have and do still use a piston/orifice in some TXV systems.
    On the older "multiflex/M" coils, you could use their Add-on TXV kit that came with a "matched" orifice. On the 3 ton coil TXV kit, it was .14 orifice, vs the .65 piston that came with the coil..


    Martin
    whaaaaa, you let all the smoke out

  6. #32
    Join Date
    Apr 2008
    Location
    san pedro,ca
    Posts
    10
    You guys where right about the blower speed it was set to high which is 4 ton cooling. How does this effect my system. The manual says for 3 ton cooling set blower speed to medium low.

  7. #33
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    68,081
    Makes it hard to get the charge right.

    Might want the contractor to come back out, and remove the piston, and recheck teh charge.
    Contractor locator map

    How-to-apply-for-Professional

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

  8. #34
    Join Date
    Apr 2007
    Posts
    623
    Quote Originally Posted by punklethal View Post
    You guys where right about the blower speed it was set to high which is 4 ton cooling. How does this effect my system. The manual says for 3 ton cooling set blower speed to medium low.
    Overall operation, and humidity removal will be affected. That medium low setting is based on a static pressure, which needs to be checked before proper speed can be determined. Thanks again for the video beenthere!

  9. #35
    Join Date
    Nov 2000
    Location
    Eastern PA
    Posts
    68,944
    Quote Originally Posted by Milk man View Post
    You know, just when you piss me off you say something like that.
    It has never been my intention to upset you or anyone else....well, maybe some others
    Government is a disease...
    ...masquerading as its own cure…
    Ecclesiastes 10:2 NIV


  10. #36
    Join Date
    Nov 2000
    Location
    Eastern PA
    Posts
    68,944
    Quote Originally Posted by meoberry View Post
    You will get a little extra noise with the piston in there along with the x-valve. (found that out the hard way) It will affect capacity and superheat. The x-valve must also have the superheat adjusted. Goodman and Amana use the same x-valve for 2 differant sizes it must be adjusted for the application.

    Rheem: I was told by the factory rep to take the pistons out and throw them away. They would cause a rattle and possible a whistle after unit sat off cycle for awhile.
    You should apply for pro-membership.

    This particular situation would have a grossly oversized piston still in place. Why would there be any noise?

    TXV's don't care about capacity other then what they are capable of metering. It is the sensing bulb temperature in conjunction with pressure that causes the TXV operation due to preset superheat measuring. Adjustments are only needed if the superheat were not correct, not because there are different capacities.

    Rheem/Ruud had back flow preventor rattles a few years back, but never heard of piston rattles. I have heard older Trane units with the whistling issue during pressure equalization after shut down, but not Rheem/Ruud.
    Government is a disease...
    ...masquerading as its own cure…
    Ecclesiastes 10:2 NIV


  11. #37
    Join Date
    Nov 2000
    Location
    Eastern PA
    Posts
    68,944
    Quote Originally Posted by Milk man View Post
    If it's a current Goodman coil and a TX_ _ _ kit with a Parker TXV I doubt they left the piston in. On those TXVs there is a little tit that is manufactured on the outlet of the TXV. I've been told that tit is to idiot proof the TXV installation. You can't leave the piston in and still install the TXV. It won’t fit. So I've been told.

    I of course have never tried to install a TXV without taking out the piston.
    Well, you got me curious enough to dig out an old orifice assembly and a new Parker TXV and you are correct. There is no way that nipple/tit on the txv will allow the txv to be installed if the piston is still in there.
    Government is a disease...
    ...masquerading as its own cure…
    Ecclesiastes 10:2 NIV


  12. #38
    Join Date
    Jun 2008
    Location
    NW Florida
    Posts
    707

    Rattles

    Quote Originally Posted by RoBoTeq View Post
    You should apply for pro-membership.

    This particular situation would have a grossly oversized piston still in place. Why would there be any noise?

    TXV's don't care about capacity other then what they are capable of metering. It is the sensing bulb temperature in conjunction with pressure that causes the TXV operation due to preset superheat measuring. Adjustments are only needed if the superheat were not correct, not because there are different capacities.

    Rheem/Ruud had back flow preventor rattles a few years back, but never heard of piston rattles. I have heard older Trane units with the whistling issue during pressure equalization after shut down, but not Rheem/Ruud.
    Yes. I had one about two years ago. It took a couple of trips to figuire out, because it would only d it when the temp. inside and the temp. outside where just right and the unit had been sitting idle for at least half an hour. It would come on and sound like a mini jackhammer going off, before you could get a cover off it would quit. Removed the piston (per service rep.) Hasn't made the noise since. That was an older Rheem 5 ton 12 seer split heatpump.
    Don't recall the model number. That was the only one I ever had do that. But made it a habit of removing pistons behind txv ever since Did not notice any change in superheat or subcooling. Customer was happy. Thats all that really matters.

    I did have a mixed system rheem airhandler on a goodman condensor. Had a very loud whistle while running. (was installed by a onetrucker) Found he had installed a txv without removing the original piston which was a .79. Didn't cool very well that way.

  13. #39
    Join Date
    Nov 2001
    Location
    east kansas
    Posts
    8,032
    Quote Originally Posted by RoBoTeq View Post
    Well, you got me curious enough to dig out an old orifice assembly and a new Parker TXV and you are correct. There is no way that nipple/tit on the txv will allow the txv to be installed if the piston is still in there.
    Thanks, I was tooooo lazy to get off my butt and walk the 20 feet to my truck and do it myself.
    Beware of advice given by some guy on the Internet.

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