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  1. #1
    Join Date
    May 2007
    Posts
    19

    Need help with evap icing, filter ok

    Getting a service guy in my area is an act of congress. The story is all the same. They are busy. The first hot day of the season, everybody's AC does not work, so they are swamped with calls. So I have ended up fixing the thing myself. Not this time, maybe you can help me.

    My unit is a long out of business Williamson five ton heat pump. The heat pump never worked, but I did not figure that out until just after the one year warranty. BTW, remember the AC guys being too busy to come out? I bought the unit and installed it myself, it is a five in one, Ok, stop laughing, I fell for the marketing hype. I really did think that a factory assembled unit would be worth scrapping a perfectly good five year old oil furnace. The AC part came with precharged components, including the lines, so I just connected it all together, and it has worked reasonable well since 1984.

    The second season, the AC was dead. Turned out the high pressure limit switch was tripped. I pushed the button, and all was well. It tripped because the reversing valxe never worked, so when I tried to use the heat pump, it immediately tripped. Since I never really needed the heat pump, I lived with it.

    In its lifetime, I have replaced the contactor, and a plenum control. No biggies.

    On a few ocaisions in the past, I had the evaporator ice up. My bad, time to clean the filter. Funny how those things can slip your mind.

    Not this time. To be sure, I took the filter out, checked all of the ducts, returns and vents, all unblocked. And the air flow seems to be normal.

    The A coil starts to ice up from the bottom. After twenty something years, I thought perhaps it might just be dirty since all of tha air goes through it. I was able to remove an end panel and looked. Nice and clean. I shot some compressed air through it, no problem.

    My research indicated that the most likely culprit is an undercharge. Why now? Is it normal for a twenty something year old unit to lose freon without an obvious leak? I have not seen any evidence of a leak, but I do not have a set of manifold gauages. I used to when I installed after market AC systems in cars decades ago. No AC technician talent needed for that, I am living proof.

    Could the true reason for "why now" be that I am replacing this entire unit with another located in a new addition later this year, and only need it to operate for about half the summer? The new unit has dedicated ducts to the ceilings.

    Anyway, the A coil ices up, starting at the bottom, about four inches pretty quickly, then gradually works its way up the coil, taking several hours to complete the journey.

    I know it is not technology correct to just squirt in a little more freon like we can do in auto systems, but I wonder if this is possible and worth a try in the absense of having a competant repairman available. I am sure the government frowns on it. Hey, I am half handy for a reason. It would sure be nice to get this thing working for the weekend. In any event, I will try, try again to get an AC guy here Tuesday, but I am leaving Wednesday for a week, and don't want to leave the family behind sweltering. Can't help the trip, something has to pay the bills.

    Thanks for your help.

  2. #2
    Join Date
    May 2006
    Location
    Vancouver, U.S.A.
    Posts
    476
    in most situations 20 yrs. is at the end of the life span for most a/c or h/p's. the precharged line sets had leaking problems, they are no longer used. best advice get a reputable contractor to look at it. if you go down the replacement road get several quotes. for most of us the price of a good a/c is not cheep. good luck

  3. #3
    Join Date
    May 2007
    Posts
    19
    Would that I could. Cheap has never been a criteria for me. Remember the part about replacing a nearly new furnace so I could get what I thought was the best unit available? As usual, I will blow my brains out on the new unit, getting the latest and greatest. AC never fails in the winter, of that you can be sure.

  4. #4
    Join Date
    Jul 2002
    Location
    Yuma, AZ
    Posts
    2,361
    Yes, there is not enough refrigerant getting into the evaporator coil. Adding gas will help. You may or may not have a leak. A leak may or may not leave a visible trace. You can probably get an EPA certification by taking a simple test and be legal. It is illegal to sell refrigerant to someone who does not have the EPA license. Best advice. Call a pro.
    "I have never let my schooling interfere with my education."
    Mark Twain
    More at: http://www.quotationspage.com/subjects/education/

  5. #5
    Join Date
    May 2007
    Posts
    19
    Pro equals best advice. You are preaching to the choir on that one. I have seen the licensing requiremends and have no doubt I could get the license, just been too preoccupied with other things, and the last thing in the world I want to do is fix my own AC.

  6. #6
    Join Date
    Nov 2004
    Location
    Michigan, Detroit Metro area
    Posts
    296
    I think it's called Murphy's Law.
    What's my post count now?
    UA Local 636

  7. #7
    Join Date
    Mar 2005
    Posts
    132

    sounds like an ideal triathalon candidate

    imagine the money you could have saved and the enjoyment you could have had if a pro had installed your system originally. imagine the money you could have made out doing your job while a lic ac pro did his for you. i imagine the real bottom line is you are not willing to pay a professional to come out and fix your unit. if you were the heat pump would have been fixed in the first few days of ownership.

  8. #8
    Join Date
    May 2007
    Posts
    19
    Please feel free to imagine anything you want, or to call me a liar right to may face if you wish. I did not have it professionaly installed because of a lack of folks available to do it, period. Believe it or not. The fact is, doing it myself was the most expensive option. It wasn't too much fun either.

  9. #9
    Join Date
    Dec 2006
    Location
    New Jersey
    Posts
    747
    you should have called a pro as soon as you realized it wasn't working correctly. they woulda been to your house already. Where i work we are swamped. friday we had to reshedule all our start ups and just do service calls. i ended up working till 1 am. i worked most of today. its first come first serve. last thing you want to tell them is you installed it yourself. alot of companies in my area will blackball u once you tell them that. your unit freezing doe not always mean you have lost your r-22. other factors can cause a ac unit that hasn't been maintained in 20 years. you do know by not having a unit installed by a professional you have no warrenty

  10. #10
    Join Date
    May 2007
    Posts
    19
    What other factors?

  11. #11
    Join Date
    Dec 2006
    Location
    New Jersey
    Posts
    747
    other factory that only a tech with proper test tools can find

  12. #12
    Join Date
    Apr 2007
    Location
    MN
    Posts
    297
    "You may or may not have a leak." lynn comstock

    If it's low, it was either never charged properly, or it has a leak. As stated, those precharged line sets are junk and always leak eventually.

    Your going to have to call a pro as you've already investigated everything you can on your own. A tech can hook up gauges and check superheat/subcooling to check the charge. If it's not that low, you can top it off and be fine. That being said, there's no way to tell how quickly it will leak out again.
    S**t or get off the pot!

  13. #13
    Join Date
    Oct 2003
    Location
    Washington
    Posts
    7,405
    What a dumb thread!!!


    You do realize you did this to yourself didn't you? When your car breaks down for lack of maintenance do you blame the manufacturer or the mechanics?

    I'm not buying your B.S. about not being able to find somebody, just isn't true, I don't care how convincing you try to be. You aren't going to get any technical help here so quit asking. It's against site rules!!

    Now get on the phone and get a pro out there. I'll betcha you could get someone out there today if you tried hard enough. Being that you waited til the last minute, be prepared to pay out your azz.

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