TraneXR 16 Air Conditioner help

[TCHB]

This one year old Trane Air Conditioner runs very quiet and then all of a sudden starts making this loud knocking noise. When this happens both the high pressure and low pressure free lines become air temperature. The compressor stops pumping Freon. It will run about 8 minutes like this until the compressor goes ourt on high temperature. After about 90 minutes the unit will start again and work great. This happens on a random basis.

 

[Riverbound]

Probably a bad indoor TXV.

 

[Riverbound]

Would be almost impossible to diagnose without hooking up diagnostic tools and having a knowledgeable tech watching what it does.

 

[Dalton]

Maybe liquid getting back to the compressor

 

[Flying_Lavey]

Is the condenser fan (outdoor fan) running the entire time?

 

[TCHB]

Is the condenser fan (outdoor fan) running the entire time?

Yes it stays running.

 

[TCHB]

Probably a bad indoor TXV.

Trane dealer replaced it Twice.

 

[TCHB]

Maybe liquid getting back to the compressor

When Trane comes out and puts all the gauges on it everything looks good. The one time they were here when it started knocking voltage looked good, and the the compressor went out on high temperature. He did not have time to hook up his gauges. He did notice the compressor was not pumping and the noise was very loud. How do you get liquid back to the compressor.

 

[Dalton]

When Trane comes out and puts all the gauges on it everything looks good. The one time they were here when it started knocking voltage looked good, and the the compressor went out on high temperature. He did not have time to hook up his gauges. He did notice the compressor was not pumping and the noise was very loud. How do you get liquid back to the compressor.

Indoor air flow issue is one way but a few things or combination of things can cause it

 

[Mr. C]

When Trane comes out and puts all the gauges on it everything looks good. The one time they were here when it started knocking voltage looked good, and the the compressor went out on high temperature. He did not have time to hook up his gauges. He did notice the compressor was not pumping and the noise was very loud. How do you get liquid back to the compressor.

Probably reading way to much into it BUT. Why the F did he not have time to hook up his gauges. He was out there on a paid ( I assume call)
That would just piss my ass off.

 

[TCHB]

Probably reading way to much into it BUT. Why the F did he not have time to hook up his gauges. He was out there on a paid ( I assume call)
That would just piss my ass off.

He just Finished going over the unit while it was running under normal conditions. I ran out to his truck and yelled that it was making the noise. He grabbed his tools and ran into the backyard. He had about one minute before the compressor went out on high temp.

 

[TCHB]

Indoor air flow issue is one way but a few things or combination of things can cause it

They added a second return duck last week that increased air flow by 25%.

 

[Flying_Lavey]

They added a second return duck last week that increased air flow by 25%.

Between the 2 txv's and adding the return duct, it kinda sounds like this contractor has little to no clue what they are doing and shooting in the dark.

Both of those things over time cause cause physical damage to the compressor.

 

[TCHB]

Between the 2 txv's and adding the return duct, it kinda sounds like this contractor has little to no clue what they are doing and shooting in the dark.

Both of those things over time cause cause physical damage to the compressor.

The contractor Trane said they have never seen a unit run normal and then the compressor starts to hammer in this fashion. 14 days ago they replaced the compressor and replaced the dryer filters.

 

[TCHB]

I do not understand the compressor running normal for days and then the banging starts. It can happens at random times with different outside temps.

 

[TPC]

Like Bildoe says hard to diagnose without being there. Could be one or two of several reasons.

Some years ago neighbor had the same issue also with repeat visits by the installers.

My impression was the installers didn't know what they were doing and we replaced the A Coil with a cap tube A coil and eliminated the problem altogether.

Next time yours starts slamming grab the bulb with your hand to see if the heat from your hand causes the valve to open and the slugging goes away.

The Condenser compressor should be shutting off when pressure is satisfied and maybe it isn't.

Maybe moisture in the refrigerant and it’s icing up inside the line. Only takes a drop.

If the installers are rookies they may be damaging the TX Valve when soldering it.

Maybe its over charged and slugging.
Could be many reasons why.
Has to be diagnosed in person.

 

[jet496]

The contractor Trane said they have never seen a unit run normal and then the compressor starts to hammer in this fashion. 14 days ago they replaced the compressor and replaced the dryer filters.

So, it's still doing it even after the compressor change?

I doubt if it's an air flow thing. Too little flow would cause icing, not overheating. Once it's dialed in, airflow shouldn't be the issue. I've been doing AC contracting for 40 years & haven't heard of anything like this.

When it starts doing it, feel the suction line at the condenser. If it's hot, then something, like a check valve, is acting up & blocking refrigerant. Since the TXV has been replace twice, it's not that. The thing is, there shouldn't be any check valves & if there are, maybe the coil is for a heat pump & is a mismatch with the condenser. Heat pump coils can have check valves in them when reversing the refrigerant cycle between heat & cool. Just thoughts.

 

[Riverbound]

Between the 2 txv's and adding the return duct, it kinda sounds like this contractor has little to no clue what they are doing and shooting in the dark.

Both of those things over time cause cause physical damage to the compressor.

Kinda the route I’m leaning after reading more. Scrolls are damaged.

 

[TCHB]

So, it's still doing it even after the compressor change?

I doubt if it's an air flow thing. Too little flow would cause icing, not overheating. Once it's dialed in, airflow shouldn't be the issue. I've been doing AC contracting for 40 years & haven't heard of anything like this.

When it starts doing it, feel the suction line at the condenser. If it's hot, then something, like a check valve, is acting up & blocking refrigerant. Since the TXV has been replace twice, it's not that. The thing is, there shouldn't be any check valves & if there are, maybe the coil is for a heat pump & is a mismatch with the condenser. Heat pump coils can have check valves in them when reversing the refrigerant cycle between heat & cool. Just thoughts.

It is a split unit not a heat pump. When the noise starts both lines become air temp quickly It acts like the compressor is not pumping when this hammering starts. . The fan condenser continues to run but the air coming out of the top is only ambient air temp not hot. Is there a compressor internal safety relief valve that operates on high or low pressure?

 

[TCHB]

Kinda the route I’m leaning after reading more. Scrolls are damaged.

Why would it run very quiet for 48 hours and then the compressor starts the knocking noise?

 

[TCHB]

Like Bildoe says hard to diagnose without being there. Could be one or two of several reasons.

Some years ago neighbor had the same issue also with repeat visits by the installers.

My impression was the installers didn't know what they were doing and we replaced the A Coil with a cap tube A coil and eliminated the problem altogether.
View attachment 1141853
Next time yours starts slamming grab the bulb with your hand to see if the heat from your hand causes the valve to open and the slugging goes away.

The Condenser compressor should be shutting off when pressure is satisfied and maybe it isn't.

If the installers are rookies they may be damaging the TX Valve when soldering it.

Maybe its over charged and slugging.
Could be many reasons why.
Has to be diagnosed in person.

Where is this bulb?

 

[TCHB]

So, it's still doing it even after the compressor change?

I doubt if it's an air flow thing. Too little flow would cause icing, not overheating. Once it's dialed in, airflow shouldn't be the issue. I've been doing AC contracting for 40 years & haven't heard of anything like this.

When it starts doing it, feel the suction line at the condenser. If it's hot, then something, like a check valve, is acting up & blocking refrigerant. Since the TXV has been replace twice, it's not that. The thing is, there shouldn't be any check valves & if there are, maybe the coil is for a heat pump & is a mismatch with the condenser. Heat pump coils can have check valves in them when reversing the refrigerant cycle between heat & cool. Just thoughts.

Yes still doing it after the compressor change out.

 

[Dalton]

So, it's still doing it even after the compressor change?

I doubt if it's an air flow thing. Too little flow would cause icing, not overheating. Once it's dialed in, airflow shouldn't be the issue. I've been doing AC contracting for 40 years & haven't heard of anything like this.

When it starts doing it, feel the suction line at the condenser. If it's hot, then something, like a check valve, is acting up & blocking refrigerant. Since the TXV has been replace twice, it's not that. The thing is, there shouldn't be any check valves & if there are, maybe the coil is for a heat pump & is a mismatch with the condenser. Heat pump coils can have check valves in them when reversing the refrigerant cycle between heat & cool. Just thoughts.

Reversing valve maybe?

 

[jet496]

Reversing valve maybe?

You shouldn't have a reversing valve, the model number is a straight AC and you should have a gas furnace inside. That being said, since this is an Inverter system, you have a variable speed compressor. It might be the variable speed controller for the compressor and/or the sensor(s). Typically I would replace the sensors the same tim since it's hard to tell which one is the culprit.

I would also try and get the refrigerant diagram from Trane, or the company working on it, to see if there are any check valves for some reason. There shouldn't be with straight up cooling, but you never know with these newly designed inverter systems, with ever changing technology. They're nice, but way too much electronics. If all else fails tell them to replace the condenser with a normal one, but this should be fixable.

 

[TCHB]

Mine is a single speed compressor and the have replaced the condenser last year. Do you think it could be the line set. That is the only thing that has not been replaced.

 

[Flying_Lavey]

You shouldn't have a reversing valve, the model number is a straight AC and you should have a gas furnace inside. That being said, since this is an Inverter system, you have a variable speed compressor. It might be the variable speed controller for the compressor and/or the sensor(s). Typically I would replace the sensors the same tim since it's hard to tell which one is the culprit.

I would also try and get the refrigerant diagram from Trane, or the company working on it, to see if there are any check valves for some reason. There shouldn't be with straight up cooling, but you never know with these newly designed inverter systems, with ever changing technology. They're nice, but way too much electronics. If all else fails tell them to replace the condenser with a normal one, but this should be fixable.

Mine is a single speed compressor and the have replaced the condenser last year. Do you think it could be the line set. That is the only thing that has not been replaced.

Look and see if there are 2 peckerheads on the compressor (wiring connections). Copeland makes a 2 stage, single speed compressor that has some internal valving that opens for the second stage. That set-up may not be configured correctly from the installers and has caused problems. Possibly.

 

[TCHB]

Look and see if there are 2 peckerheads on the compressor (wiring connections). Copeland makes a 2 stage, single speed compressor that has some internal valving that opens for the second stage. That set-up may not be configured correctly from the installers and has caused problems. Possibly.

Ok I will check it out. The compressor that the removed was a Samsung and the replacement was a Samsung.

 

[Flying_Lavey]

Ok I will check it out. The compressor that the removed was a Samsung and the replacement was a Samsung.

Interesting. Trane broke off the relationship with Samsung a few years ago. Like 3 or 4.

 

[TCHB]

It looks like one connection on compressor.

 

[Dalton]

Mine is a single speed compressor and the have replaced the condenser last year. Do you think it could be the line set. That is the only thing that has not been replaced.

If they went from r22 to r410 without replacing the lineset that could be a problem

 

[TCHB]

If they went from r22 to r410 without replacing the lineset that could be a problem

The old air conditioner was 17 years old. Not u about the Freon.

 

[Riverbound]

I wound have them came back out.

There’s soeltjjng they are missing. I’m still leaning towards txv. It’s the only thing that would make sense.

But there are so many variables. That something is being missed.

If they use digital gauges and happened to take pics that would be a good start to post up pics here.

 

[Dalton]

The old air conditioner was 17 years old. Not u about the Freon.

Was a home warranty company part of the work?

 

[TCHB]

Was a home warranty company part of the work?

No. The Trane dealer has been the only person trying to solve this issue.

 

[TCHB]

I wound have them came back out.

There’s soeltjjng they are missing. I’m still leaning towards txv. It’s the only thing that would make sense.

But there are so many variables. That something is being missed.

If they use digital gauges and happened to take pics that would be a good start to post up pics here.

Yes they use a digital gauge set when checking. The repair tech has been great but can not figure it out and why so random. Trane factory has been zero help! I will take a picture of his digital gauge. Last time out I was looking at the digital set and he commented it looks perfect. Why does the compressor start the loud noise and it stops pumping. He was thing the internal relief valve was opening and sending high pressure gas back to the suction side. this was happening inside the compressor.

 

[Riverbound]

Yes they use a digital gauge set when checking. The repair tech has been great but can not figure it out and why so random. Trane factory has been zero help! I will take a picture of his digital gauge. Last time out I was looking at the digital set and he commented it looks perfect. Why does the compressor start the loud noise and it stops pumping. He was thing the internal relief valve was opening and sending high pressure gas back to the suction side. this was happening inside the compressor.

There’s something else going on. Which is why the issue is happening even after compressor replacement. Most likely what happens is. Whatever is happening happens. And then the high pressure side spikes causing the unit to go into high pressure bypass mode. And then compressor overheats. Once it settles down and cools down restarts.

Still all the tells of a bad/stuck txv

 

[Riverbound]

The specific items needed are.

Super heat
Sub cooling
Liquid temp
Suction temp
Vapor saturation temp
Low side pressure
High side pressure.
Outside ambient temp.


Inside measurements.
Return air dry bulb and wet bulb.
Supply air dry bulb and wet bulb.

And for arguments sake.
Liquid line temp at txv
Suction line temp at coil.

 

[Riverbound]

A refrigerant contamination issue could also be possible as well. If they didn’t flush the lines and run a proper vacuum on the system.
Inverter systems use a different oil that will react and cause a crystal to form in the oil.

 

[TCHB]

A refrigerant contamination issue could also be possible as well. If they didn’t flush the lines and run a proper vacuum on the system.
Inverter systems use a different oil that will react and cause a crystal to form in the oil.

He vacuumed the system for 45 minutes when he installed the new compressor.

 

[TCHB]

The specific items needed are.

Super heat
Sub cooling
Liquid temp
Suction temp
Vapor saturation temp
Low side pressure
High side pressure.
Outside ambient temp.


Inside measurements.
Return air dry bulb and wet bulb.
Supply air dry bulb and wet bulb.

And for arguments sake.
Liquid line temp at txv
Suction line temp at coil.

I will find out what these readings are. He said all the readings are where they should be!

 

[Flying_Lavey]

It looks like one connection on compressor. View attachment 1141949

Is nobody seeing the junk around the copper to steel connections of the compressor? There should not be anything there at all. Even after the compressor replacements.

I'd really look into getting a second opinion on it. There are quiet a few things that make me question their knowledge and installation capability at this point.

 

[Rajobigguy]

Ok I’ll take a stab at this.
First off that is one of the sloppyist soldering jobs I’ve seen. If they got a big glob of solder in the discharge line it could be creating a restriction and cause a localized icing problem which could cause high side pressure to raise to the point that it open the internal bypass and the cooling stops until the ice blockage melts then it’s back to normal operation until it forms the next ice blockage.

 

[Riverbound]

Is nobody seeing the junk around the copper to steel connections of the compressor? There should not be anything there at all. Even after the compressor replacements.

I'd really look into getting a second opinion on it. There are quiet a few things that make me question their knowledge and installation capability at this point.

It looks like that heat absorbing putty for brazing. I saw that as well and zoomed in.

I agree with the second opinion. Or at least get a higher level technician out (if they even have one)

 

[Riverbound]

Ok I’ll take a stab at this.
First off that is one of the sloppyist soldering jobs I’ve seen. If they got a big glob of solder in the discharge line it could be creating a restriction and cause a localized icing problem which could cause high side pressure to raise to the point that it open the internal bypass and the cooling stops until the ice blockage melts then it’s back to normal operation until it forms the next ice blockage.

It wouldn’t ice up internally and cause a blockage. The refrigerant itself doesn’t freeze.

The blockage or restriction would cause a high pressure situation, but In previous posts the OP stated unit was told everything is correct with the readings.

 

[TCHB]

It looks like that heat absorbing putty for brazing. I saw that as well and zoomed in.

I agree with the second opinion. Or at least get a higher level technician out (if they even have one)

Yes heat absorbing putty.

 

[Flying_Lavey]

It looks like that heat absorbing putty for brazing. I saw that as well and zoomed in.

I agree with the second opinion. Or at least get a higher level technician out (if they even have one)

Maybe so. I've never used the putty and really don't see much need to do so here. Plus the fact that the tech didn't even clean it off? Pretty sloppy. Then looking at the solder job on the discharge line a little further, it almost looks like they used a smaller piece if pipe as a nipple.

All these things that can be seen aren't cauing the problem, but they do indicate a pattern which makes one question the only company that has worked on thr unit's ability.

 

[TCHB]

It wouldn’t ice up internally and cause a blockage. The refrigerant itself doesn’t freeze.

The blockage or restriction would cause a high pressure situation, but In previous posts the OP stated unit was told everything is correct with the readings.

Yes two techs watch it run for about a hour and took the readings at the condenser unit and went in the attic to check on something?

 

[TCHB]

Yes heat absorbing putty.

First time I have seen someone use heat absorbing putty.

 

[TCHB]

It has been running over 24 hours now normal. This is what is so puzzling.

 

[Riverbound]

First time I have seen someone use heat absorbing putty.

I used it once…… threw it away after that. My vendor swore by it so figured I would give it a try. Went back to the wet towel method I was taught and always worked.