Trane Heat Pump - Confirm my fears?

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I have a Trane XE1200 1.5 ton heat pump system in my bonus room that is my office. I am a pretty good DIY'r with some history of commercial refrigeration in the 60's. I'll probably get flamed but, I am tired of paying for service calls with no results. This is my first heat pump.
A few days ago, it started using the heat strips constantly where it seldom had ever used the strips and the air handler runs constantly to keep up. OD temps in the 40's which should be easy for it. All of the lines inside the unit felt cool at about equal ambient temp. I pulled the diagrams and checked the pressures and found both pressures equal about where they should be for static ambient temps with R22. The thermostat is calling for heat and the contactor to the compressor is closed.
I checked again yesterday with temps in the upper 60's in cool mode. Found the same - thermostat calling for cooling and the compressor contactor closed with voltage to the compressor feeds. Pressures are equal around 135psig. Could not detect compressor running. (I don't hear well) Voltage from contactor to compressor at 127 volts phase to ground and 248 volts phase to phase which tells me the compressor should be running. Checked for continuity in compressor with feeds disconnected from contactor and found both legs at infinity. The pressure sensor on the compressor is closed. If I am reading all of this correctly, the compressor is dead.
The reason I am asking is that the unit was not cooling well in the fall. I had the service folks who installed the unit when we built on 2000 out several times to check it. Even though I was seeing what I believed to be low pressures, they informed me this was OK. When I first started having cooling problems, I was getting pressures like 150/82 on a 90 deg day with the unit running constantly. I have already spent over $500 trying to get this resolved with the service folks and the only thing they have done is test and add refrigerant. The pressure have never increased above about 180 on the high side although the low side was about 125 the last time I know the compressor was running while being checked. This is an R22 system. I think the compressor has been limping for some time. Am I missing something or is it time to replace at least the compressor? Is a 6 year old system even worth a compressor when install labor is considered?
Any ideas or pointers greatly appreciated.
Lugnut
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The replacement will be your second.

Obviously, the compressor should be running, and obviously something is wrong.

And we can't hear it here either. Did you test for the other indication that would verify that it is running? You know, the one that doesn't involve getting the gauges out, and works well regardless of the ambient noise level. That measurement would answer the larger question, also.

You have a 3 phase compressor in a resi. application? Or, did you really mean you measured line to ground?

The pressures, or the fact that you don't think the unit is cooling well?

Assuming the compressor is bad, it may or may not be under warranty. This also depends on whether the tech. took notes on the fact that you've been screwing with it. You will pay to have it replaced. The information that you have provided regarding your tests does not definitively lead me to believe that there's an issue with the compressor.

Stop screwing with it, and try a different tech. if you don't like the one that's been coming out. Also... and this is REAL important. STOP telling people - especially HVAC techs - that you've been releasing refrigerant to the atmosphere. That itty bitty amount that leaks out when you take your 35 year old gauge set off is plenty to get you nailed by the EPA if you piss off the wrong person.

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On Sat, 25 Nov 2006 12:23:44 -0500, "Mo Hoaner"
Thanks for your response.

I was afraid of that. I may try to negotiate with the service folks who have already not done me any good at diadnostics.

If you mean whether I tried placing my hand on it when it should be running - yes - and felt absolutely nothing other than a dead compressor. I also used my clamp-on amp meter on the feeds and got no reading. The lines are all cool.

It is a single phase 230 volt unit. I have 127 on each leg to ground and 248 across the legs on the compressor feeds on the compressor side of the contactor.

The unit has never had a problem heating or cooling this space. When it became obvious that it could not maintain the ID temp of the roon at less than 90 on an 80 degree space that it had neve had a problem maintaining 72 on similar days, it did not appear to be performing well. I used my guages and checked it finding what appeared to be low pressures for the conditions and call the service folks. They said it was fine and only need a bit of refrigerant. I shrgged it off while the warranty expired. It got worse.

It was well within the 5 yr warranty when the tech came. It is now out of warranty and out of my pocket. The installers tech was the first to ever screw with it after installation. It was built in 7/2000. Unless Trane has extended their warranty without notice, it is all my nickel. I would be more than happy for them to participate. I was under the misinformed impression that Trane was the best and should be good for a considerably longer time. I had to have the Trane LPG furnace on the main level replaced a couple of years ago. In this area, my prior heating/cooling units have gone 12-15 years with no problem other than annual checkups.

Thanks, I'll only screw around with it if they experts I hire can't help. I would have though the folks who installed the systems during construction would have been a good choice for maintenance. I appear to have been wrong at this point.
Lugnut
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Compressor is probably toast.... but you got a Trane!!
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On Sat, 25 Nov 2006 12:08:24 -0600, "Noon-Air"

Let's assume it is toast for the moment - or, at least, I think it is. Do you have a recommendation. My thoughts now are to go with a Lennox OD unit of similar specs since this one seemed to work well untill it didn't. I am not inclined to replace the air handler as it is in the attic and would require some structure or roof to be cut out to replace. I am sure as hell not in a mood to cut thru the roof.
Lugnut
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<snipped>

Why go with a lesser quality piece of ...(Lennox) equipment??.... for a lot less than a new system, you should be able to get the compressor replaced. Just find a *COMPETENT* tech to do it.....and this doesn't necessarely mean it has to be a Trane dealer.

If the outside unit is replaced, then the inside unit needs to be replaced also so they are matched and will work as they are supposed to, and you won't have any warranty issues if the installer decides to take a powder. If you have to cut a hole in the roof to get the air handler in or out, then it sure as hell doesn't comply with code and *NO* inspector will sign off on the work.

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On Sat, 25 Nov 2006 16:34:06 -0600, "Noon-Air"

The units I spec'd for my homes and offices before this were all Lennox with zero problems for more than 30 years. I decided to go with what was reputedly the Cadillac of the business this time and have had a bit of bad luck with both units. There is only one Trane dealer in this area and I am not inclined to call upon him based on my lack of joy in getting this problem resolved and being jockeyed past the warranty expiration for the compressor unit after it first exhibited signs of failure.
From what I have been able to learn from limited reading, bad pressures in a heat pump are basically caused the same way as in straight a/c systems. The biggest twist in the pump system is the reversing valve. I can see how a leaking or stuck valve can result in low pressure and may (will) also eventually lead to compressor failure. This one appears to be electrically dead at this time. I believe the key to this has been in the pressures and temperatures during operation. If I do replace the compressor, how can I be sure the reversing valve was not reponsible and cost me more after the compressor is replaced to get it back online operating properly?? If I read this right, there is no way of testing the reversing valve other than the solenoid short of putting it back to work to see what happens - is this correct? I feel I have been given the mushroom treatment by the installer now for a year and a half. I do greatly appreciate any info I can get to help in making an intelligent decision on how best and who to get in repair or replacement of the unit. I hate someone trying piss in my face and tell me it's raining!!

This is not a job subject to inspection unless I am re-roofing the house. Nevertheless, the lineset and AH are not going to get replaced quite simply because of the structural work that would undoubtedly run into the thousands to pull it off in this installation. That part of the repair is not an option even if it works at less than optimum. If I have to do that, I will scrap the heat pump and install an attic furnace plus A/C unit. At this point, I am not impressed with the life expectancy of heat pumps or the availablility of competent repairmen in this area.
Thanks Lugnut
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do you understand a multi-meter?

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On Sat, 25 Nov 2006 17:17:15 -0500, "daytona°"

I have a decent Fluke meter and can get hands on whatever I need to test or repair if I have to. My problem here has been the lack of difinitive values that I may look for. For that reason, I have only looked at the basics as I recalled from my days with the chiller units.
Thanks Lugnut

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Do an ohms test between the Start, Run and Common wires in the control box...this way you do not have to get into the compressor. Some compressors are a little difficult to get to...other are very easy. The test is to see if the windings are open....I don't want to get into shunted and weak. Shorted winding would blow the breaker or pop the fuse quickly. Could be a burnt off terminal at the compressor, could a faulty internal overload ...who knows. It's hard to diagnose with out being there

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On Sat, 25 Nov 2006 17:17:15 -0500, "daytona°"

Just wanted to ask if by chance you are in the Daytona area and been there for a while. I had a friend there in the HVAC business for years. He disappeared after the divorce to some black hole in MA.
Lugnut

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NO....in Western PA....I had a Daytona boat (36' Cat)...that's where the handle comes from. Also fake email...keeps all the flamers and spammers away

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It was me.... I'd check the start capacitor before you go any further.
Jake
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On Sun, 26 Nov 2006 00:55:29 GMT, Jake

I have wondered about the start cap on the unit but, have no way to test. I suppose I could just put one in since thay are relatively cheap. The condenser fan does runs as it should when the contactor closes. I cannot detect current to the compressor even though it has line voltage on each feed. There is a relay to the caps that is closing as it should. This is a Trane TWP018C100A3. I found the schematics inside the unit. I have seen a couple of compressor with bad start caps but, they always had a thump when energized and tripped the breaker after a few seconds. I am not getting that here - ammeter reads zilch when powered. Is there a simple way to test the caps short of burning a good screwdriver?
Thanks Lugnut
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lugnut wrote:

With the compressor cold.... ie not tried to start in a while... check the resistance between the S and C.. and the R and C on the compressor.
Do this with the unit disconnect OFF and you'll have to pull the little 'flag' connectors off their various terminals.
R and C is going to be between the two phases of your 240 circuit on the contactor load side. Again, you'll have to pull the connectors off because otherwise you'll read other stuff.
S and C is going to be between one phase on the contactor load side and the capacitor lead from the start relay going to the compressor S terminal.
You should get continuity between C AND both S/R.
If you don't... an internal overload (or the compressor motor) has opened up and it'll never run again.
I don't know what the labor rates are in your area... but I KNOW I'd consider a compressor changeout on one that young. I'm not an HVAC guy but a pretty competent electrician that's changed several. It's not a DIY job, though... unless you wanna spend some serious money on tools and training.
Chances are.. there is something else wrong here, though. Get a good tech to take a look-see. You don't have to replace the indoor unit... but replacing the coil to match the condenser is always a good idea if you go that route.
Boy... I'll bet I've made some folks mad here... but you seem to have a good grip on things.
Good Luck.
Jake
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On Sun, 26 Nov 2006 03:11:32 GMT, Jake

Thanks, Jake. I am going to print this and give it a look/see tommorrow. It may take me a while to learn what I need to know on this but, I want to know WTH is wrong with it that the installers were unable to detect. They were just here a few weeks back for not cooling and gave it a clean bill of health. If the compressor has to be replaced, it won't be by me. I just want to make sure it is the compressor before I pull the trigger on a problem that could have been more reasonably repaired. I just got an e-mail from a shop about 100 miles away that has an exact model complete Trane outdoor unit for $695 loaded on my truck. He said he has a couple for a job that he ordered for a contract that fell thru a few years back and would still have full warranty since they had never been installed. He won't install for me because of the distance. I have no idea what a tech would charge to hookup and charge with no warranty responsibility. They may want to charge as it they had installed a complete system from their supplier in which case I will brush up my brazing skills that haven't been used in about 15 years. So far they are suggesting a compressor replacement is likely to be over $1200 with no guarantee that it is all that will be needed. I have no idea at the moment if those prices are real world right now. It may be a decent price for all I know.
Thanks Lugnut
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A couple of thoughts. If the compressor did burn out, it's very possible that the system is full of acids, and other corrosive chemicals. I'm not sure if acid neutralizer filter driers are still made, but it's a good idea to ask for one.
I usually figure three hours for compressor change for refrigeration equipment. Might be more for an outdoor Trane unit. But to change the entire outdoor unit should be three hours or so. Including the freon recovery. Figure five or six pounds of new freon into the price.
695 for the unit on the back of your truck sounds fair. 1200 for the compressor, installed, sounds reasonable. But given those two prices, I'd call around and try to find a tech to install the condensing unit. May as well get the new contactors, reversing valve, and so on.
--

Christopher A. Young
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Dear Lugnut, "I cannot detect" very often means that the writer does not own the equipment necessary so that he can detect the value. People who have the equipment often write "I read zero...." Reading farther, it appears you have an ammeter, and can use it.
Which is it? Do you lack the equipment, or are you reading zero current to the compessor while it's getting 220 volts applied?
--

Christopher A. Young
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On Sun, 26 Nov 2006 12:32:52 GMT, "Stormin Mormon"

I have the meters. The only thing I do not have are the digital temp sensors which are not much good in what appears to be a non-functioning unit. I could not detect meant that I could not hear or feel the compressor running nor was it warm as I would expect. I used my ammeter on the feeds to the compressor and found a "0" reading. I went further and checked the voltages by the diagram in the unit. I found what apears to me to be correct voltages from the thermostat to the controls and correct line voltages. I found the compressor contactor closed when the stat calls for duty and open otherwise. There is 127volts on the compressor side of the contactor of both feeds to ground and 248 volts across the feeds as it should be. The compressor sensor is "closed" according to my meter. I believe this qualification has to be met for the contactor to close providing voltage on the compressor side of the contactor as it controls power to the contactor solenoid preventing it from closing if the sensor is open.
Another thing I have noticed is the green LED on the defrost control board is flashing 3 times which can indicate any one of several things but, the docs I have are a clear as muddy water on how you would proceed from there. One of those faults is low refrigerant charge. I should be able to rule that out in the case of a no start/no run compressor if the compressor has voltage and the sensor is closed and, I have what appears to be at or above correct static pressure for the ambient temp which should indicate at least a partial charge. The docs indicate a single flash to be normal. I am a bit confused as to why there would be voltage to the compressor if a hard fault has been detected since the compressor sensor is fed from this board. I believe the board uses this connection to determine whether there is a charge in the system. Again, I believe a lack of voltage here would prevent the contactor from closing. Is it possible that the closed compressor sensor is the indication of a low charge instead of an open sensor? If this is the case, I still would not understand why there is line voltage to the compressor.
Your help and comments are greatly appreciated.
Lugnut
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wrote:

Lug, I hate to say it but your posts sound more and more like you are going to perform the do-it-yourself route. Fortunately, Im in an area where the hvac guys are a dime a dozen. Unfortunately, there are only a couple that know what they are doing. Just so you know, a properly sized and installed heat pump system will last a VERY long time. A HUGE part of that is finding a company that knows how to pull a proper vacuum. I am 100% convinced that a proper vacuum leads to a long compressor life. Short of all that being said, you need to have your system check and or replaced by someone that knows what they are doing..............not You! Happy Hunting, Bubba
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