Trane XR12 3ton freezing up again
This is my 3rd or 4th post on this unit since it was installed in 2006. The first time it started freezing up was a year after installation in our new house which is 1600 sq ft. The coil in the attic unit had rusted out and needed to be replaced. We were 2 months out of warranty and had to pay all the labor costs which were pretty hefty. A few months ago, the unit froze up again. It was a clogged drainline which my husband cleared and everything was fine. Now it is freezing up again. It's not the filters or drainline. I can't understand why now. Summer heat is not nearly as bad as it was (day time temps were 84 here today) and the humidity is lower. (We live in west central Florida) The t-stat is set at 76. The strange thing is that it is freezing up after 6 in the evening. It makes it through the heat all day long and yet an hour or so before sunset, it freezes up.
So what could it be this time? I have my suspicions and they scare me.
the blocked drain line didn't cause a frozen coil
sure seem to be some challenges with this system in only 2 years...
actually it is probably freezing over all day and in the evening when you notice it the system is a big ball of ice.
you posted the OD unit model but not the indoor unit model # kinda need that info as well.
Yes, hubby just set me straight on what happened with the plugged drainline. It apparently back up and filled the drainpan which set off the overflow switch and turned the unit off. My bad! Sorry!
Yes, this Trane has been giving us a difficult time. I gotta say, I'm not nearly as thrilled with this one as I was the Trane on our old house! Ok, the model number in the attic is TWE036P13FB. I hope it helps!
well, the drain line could have been clogged or your icung problem may have existed at that time.
sometimes find a system that has iced up and thawed out itself, and it can overflow the emergency pan.
i would have a technician come out and check the refrigerant charge on the system. you say it is icing up in the evening hours. is you t-stat set point the same (76) in the evening as well?
are you located near the beach, salt air and all to go with it? i still question the indoor coil leaking after only 2yrs of duty. but i have run across some. i am thinking the still maybe a leak in the system that has not been located yet. i may be wrong, after all i am trying to diagnose your system over the internet without much technical info.
maybe call a different HVAC contractor out this time to get a second set of eyes and service technique on the job or maybe since the expense was just paid out for the indoor coil replacement see just what your contractor is willing to do to get your system running correctly i would try to see what the guy that changed the coil would do, and if the results are the same, get a second opinoin
the cause can either be low refirgerant charge or low airflow. so inless you waited til the filter looked like a floor mat before you changed it, the indoor fan relay is not functioning properly, or there is a duct work issue, then it would be refrigerant related. that indoor unit uses a piston for a metering device (if iremember correctly) then a bad metering device is pretty slim...
Not too close to the beach...I wish I were sometimes! We are about 22 miles from the beach. Noone else around us has the problems that we do with this unit. We built this new house right in front of our old house and never had issues with our old Trane which was 20 years old! Yep, we loved that AC unit! We have well water and that was once mentioned to be a possible problem so we had a aerator put on the well (the well is about 75 feet away from the outside unit.) and the water tested out showing the only problem to be a bit of "hardness".
The filters are changed every month or as needed because my son has pretty bad allergies. I'll start hunting for a new AC tech. Man, I hope this thing isn't leaking again. We just got the credit card paid off for the last time this happened.
Thanks again for your help Beachtech! And yes, I understand what you mean by the "internet diagnosis". I appreciate your thoughts and advice.
What type of air filter are you using.
It wouldn't be a 3M filtrete filter would it?
Also check to see if the outside unit is running after the inside blower shuts off. You could have a bad contactor on the condenser that keeps it running.
Would be alot less expensive than the probable cause of another rusted evaporator coil.
No, the filters are not 3m filtrate. These are called EnergyAire by Flanders and we buy them from Lowes. They are white and made from a thin felt-like material. It funny you mention it because I noticed somthing with them this afternoon. There are 2 filters on this AC system. The big one in the hallway is "ballooned" up like the intake is trying to suck the whole thing through. Is this too much resistance that might be causing the problem? We left the AC off all night with just the fan on to help it dry. This morning we turned it back on to see what it would do. This afternoon, it is running and cycling like usual while maintaining the usual 76 that it is always set for. We have a thermometer that hangs in the register closest to the air handler. It is currently blowing at 62 degrees. Outside temperature is about 84 with a light breeze.
Yes, the outside unit starts to make droning noises once the inside unit freezes up. When this happens there is no air flow at all from the vents. We thought it was because the outside unit was still trying to cool the house. The whole system has to be shut down to get the outside unit to turn off once the vent flow stops. Once the air handler thaws out and the air circulation through the vents comes back, the outside unit cycles normally.
Just a question for you guys...
In all the houses we have lived in through our lives, the air handlers have always been either in the garage or in a special closet in the house...usually the hallway. This unit is different to us in that the air handler hangs up in the attic of this house. We were told that the attic is the new "home" of air handlers. I gotta say...we have had nothing but problems with ours. Do you guys find more problems with the attic handlers or are we just "lucky"? Just wondering....
Thanks for your help!
Lots of air handlers in attics.
Not really more break downs in them.
Yes, the filter balloning like that, is a sign that the blower is struggling ot get air.
Air handlers in the attic is the "new home" that's a good laugh. I work down here in Florida and the attic is the old home. No new homes are really being built with attic air handlers. I would call Trane customer support and ask them for a local dealer's number and call them to service your unit.
if it is 76 in your home supply temp should be around 56 your system may be restricted
or low on charge.
I'm glad to hear that the attic installations don't seem to have any more problems than house/garage air handlers.
I really don't know what to think at this point. We have been keeping a close eye on it and right now it seems to be doing the job. I rechecked the register thermometer after the system had been running on it's latest cycle for a few minutes. The register temp is 60 degrees on the nose. The unit is cycling normally and maintaining 76 degrees. It's 11:07 pm here, breezy and probably mid 70's outside.
An old AC tech we once had told us the regular blue fiberglass type allowed to much dirt to get through and would clog the air handler itself. Between that reasoning and my son's allergies, we have been using allergy type filters. If the old information is wrong, please let me know! What filters do you recommend since the ones we have been using might be "choking" the system? It's also the time of year that we turn the register up to 78 since the weather is getting cooler. Even though it's just 2 degrees, would that help?
We really appreciate everyone's help! You all have been very helpful!