bumpski
newbie
Reged: 08/18/04
Posts: 16
|
|
Hi
My Trane XL14i heat pump compressor makes a very load groan for about 2 to 8 seconds at the end of many defrost cycles. I have a video of my compressor reversing with sound for your entertainment. Please turn up your sound so you can hear the normal compressor background sound level.
http://www.bobshowto.com/_videoBHT/HeatPumpMovie.wmv
My tentitive research indicates this may be a problem with overcharging.
The compressor has been left in this state for the entire winter, my installer was aware of this loud noise and has expressed concern but hasn't been back for repair. This system is running fine otherwise and my main concern is the compressor life span is continuing to shorten. Trane and the dealer are protected by a 10 year warranty. The XL41i has an excellent reputation for durability and longevity and I hoped the compressor would last 15 to 20 years. Now perhaps it has had 6 months worth of abuse, shortening the lifespan from 15 to 11 years, no problem for Trane or the dealer! I am in contact with both my installer and Trane regarding this. My installer is being a bit unresponsive and it has been mentioned the XL14i using R410A refrigerant is a new system which may have quirks to work out. I'm pretty sure its been around for 5 years now. Another note is upon commissioning the air handler evaporator coil failed, slowly losing refrigerant during air conditioning season. At first the coil froze up, then after about half a day I shut the system down realizing there was a serious problem, so the compressor was exposed to this abuse as well, which the installer shrugged off and they of course replaced the evaporator coil (indoor) free of charge.
So I'm looking for opinions about this loud groan and its impact on the lifespan of my compressor. Suggestions much appreciated as well
Thanks in advance!
--------------------
Bob
|
HeatPro
Carpal Tunnel
Reged: 07/30/04
Posts: 23546
Loc: South New Jersey
|
|
When a condensing unit goes into defrost mode, it is subjected to having the suction tubing reversed with the hot gas. This has to be absorbed by the compressor until it equals again. As the new refrigerant makes the pressures increase by the range of 120 psig to sometimes 400 psig, this is a greater difference than the older refrigerant units, so it can cause more and different noise.
The situation that can make the greatest difference is the amount of charge. As your system lost its charge, the result will depend upon the charging method and assurance that the right amount was cleanly installed. That can not be assured without total evacuation and charging the refrigerant in by weight. Once the proper charge is assured for the unit with its lineset length, then other problems have a starting point to be examined.
Such a sound during a reversal to defrost, especially in warmer weather with higher pressures is not unusual, so readings taken of the operating pressures in comparison with the factory charging charts and amperage/voltage reading during operation are all that the factory troubleshooting specialists can use to examine for troubles. Either the tech can provide that and compare with given expected parameters or give the same to the factory troubleshooters.
If all that were necessary was to hear a sound to give instant assumptions, HVAC heat pump training could be done in short time with just sound bytes. It takes some time before the sounds are recognized as indicators; being at the location of a few hundred units during the reversal under all weather takes some time for techs to gain experience.
--------------------
Friends tell people how to live past 60.
|
bumpski
newbie
Reged: 08/18/04
Posts: 16
|
|
Thanks, I new the diagnosis would not be easy.
Just to be clear this loud groan is at the very end of the defrost cycle for 2 to 9 seconds, while reversing, and it is very loud. As a home owner I would call it unacceptably loud. This to me in itself seems abnormal. An excessively loud noise can be a definitive good or bad indicator, like a bad muffler in a car. If the exhaust is abnormally loud you know there is a problem and if you leave it that way you wonder how long the car itself will actually last.
The compressor does not make such a loud sound when starting up, or initiating the defrost cycle. Granted it is a new system using R410A. 400 psi operation is indicated on the label. I know very little about charging such a system. I didn't see any sign of a scale being used while the system was recharged, or initially charged by the installer. The same installer did the initial charge and the recharge. ( I guess my wife and I sucked in a lot of R410A too! )
I've heard other heat pumps reverse and have never heard a sound nearly this loud. The length of the "groan" varies with temperature. Of course so do the number of defrost cycles. In my direct contact with Trane, they have already suggested replacing the "defrost control board", fine, good, but what degradation has occurred? I don't think I'll get an estimate, I will try to. (Plus this just doesn't even seem like an electronics problem.)
To go with my analogy, my car with the whole in the muffler will probably run fine until just after the warranty runs out. Then I have a hole in my floor boards and a lot of burnt valves. I guess I hoped to hear, wow, that is too loud and probably does suggest an overcharged system. My installer will be coming by soon, I'll try to pass on his corrective action.
--------------------
Bob
|
HeatPro
Carpal Tunnel
Reged: 07/30/04
Posts: 23546
Loc: South New Jersey
|
|
Fortunately, one feature of the new refrigerant is that it takes about 1/3rd less to do the job.
The groan is coming from the compressor under the change of pressures. Scroll compressors are well-known for producing sounds upon shut-down equalization and this change of pressure is similar. Now that you have notified the tech and the factory of the problem, it should have some affect upon the warrantee if there is a failure and some effect upon the design engineers at the factory.
--------------------
Friends tell people how to live past 60.
|
|
Previous
Index
Next
Threaded
Edit
Reply
Quote
