Announcement Announcement Module
Collapse
No announcement yet.
fan or txv? Page Title Module
Move Remove Collapse
X
Conversation Detail Module
Collapse
  • Filter
  • Time
  • Show
Clear All
new posts

  • fan or txv?

    Have a customer's rental with a 4 year old trane 3 ton ac and a matching furnace. The evaporator coil froze up about 3 weeks ago. went out, cleaned everything adjusted pressures. everything worked great until today, when they called with no AC.

    Get there and the evaporator was froze up again. Blower fan is already set to high for cool. Is there a way to test the blower to see if it's working properly without just replacing it and hoping it works? "I should know the answer to that, but I don't"

    Could it be a txv issue instead? I've got a txv that will work I bought for a different project that ended up wanting a new unit entirely.
    No, it's not rocket science, it's plumbing and unlike rocket science it requires a license.

  • #2
    Re: fan or txv?

    are the filters clean, is it running more than normal or set cooler then normal? are the ducts sized correctly?
    Push sticks/blocks Save Fingers
    ~~~~~~~~~~~~~~~~~~~
    "The true measure of a man is how he treats someone who can do him absolutely no good."
    attributed to Samuel Johnson
    ~~~~~~~~~~~~~~~~~~~
    PUBLIC NOTICE: Due to recent budget cuts, the rising cost of electricity, gas, and oil...plus the current state of the economy............the light at the end of the tunnel, has been turned off.

    Comment


    • #3
      Re: fan or txv?

      did you check running and start amp's on the blower?
      sigpic

      Comment


      • #4
        Re: fan or txv?

        First thing after thawing out the coil is check the refrigerant pressures. If the suction pressure slowly drops from a normal reading it's a good indicator you have an airflow problem. If the pressure is low from the get go add some gas to it in small quantities. If nothing changes pressure wise check the Comp. and TXV.

        Usually it's fairly simple to tell if you have enough airflow across the evap. coil. I stick my hand in front of the air registers. If you want to impress the customer pull out the anemometer and a calculator. Been doing it long enough I can tell if it's an airflow problem or something else.

        Comment


        • #5
          Re: fan or txv?

          this is the first year it's been an issue for them, so I have to assume the ducts are sized properly. filters look good, just 1 inch cloth looking filters.
          I thawed them out and restarted the system for today. I'll go back tomorrow to figure out the problem.

          What am I looking for on the amp draw? just check the rating plate and compare it?



          James, if it's a low gas issue wouldn't the outdoor unit being the one freezing over?

          Go easy on me, this is only my second summer working on hvac systems.
          No, it's not rocket science, it's plumbing and unlike rocket science it requires a license.

          Comment


          • #6
            Re: fan or txv?

            Originally posted by MoJourneyman View Post
            this is the first year it's been an issue for them, so I have to assume the ducts are sized properly. filters look good, just 1 inch cloth looking filters.
            I thawed them out and restarted the system for today. I'll go back tomorrow to figure out the problem.

            What am I looking for on the amp draw? just check the rating plate and compare it?



            James, if it's a low gas issue wouldn't the outdoor unit being the one freezing over?

            Go easy on me, this is only my second summer working on hvac systems.
            No, the evporator coil will ice over.

            If the unit is only 4 years old it should be under warranty.

            Comment


            • #7
              Re: fan or txv?

              sorry i just cut and pasted from my other link ....can't type fast.

              Try taking the TXV bulb lose and get a glass of hot water and a glass of cold water(see where I'm going with this?) try submerging the bulb in one at a time and go observe the head and suction pressure. if there is no change then the power head of the TXV is dead (gas leaked out) if it gets better with the hot water it is leaked down some and you might be able to squeeze it down with some plyers for temporary until you get the new head (or TXV)... pump down unit get new power head (if it can be changed) and replace it. If it is a "sporlan" you should find a # stamped on it like "45" or "55" or "65" go get one of the same #. the model# on it may be "OEM" so look for the stamped one. also check if the system has a liquid line filter dryer and see if it is cooler on the discharge side or sweating , this would indicate that its clogged. good luck and let us know what happened.

              Remember that you shouldn't always think "low Freon" first. sounds like your on the right track.
              ROMANS 10:9 confess with your mouth that JESUS is LORD and believe in your heart that GOD raised him from the dead and you will be Saved.

              Comment


              • #8
                Re: fan or txv?

                I am not going to go easy on you. It's people like you that give the rest of us a bad name. The Qs u asked tell me that you didn't go to a reputable HVAC school and you're just winging it. Since i doubt that you'll stop masquerading as a HVAC Tech, put on your big boy pants and please go to night school and LEARN the trade.

                Comment

                Working...
                X