Skinny line is chilly. No cooling. How bad?

[cano]

Is the restriction before or after the cold area? If there's no drier where do you think the restriction could be? Thank you.

[ga-hvac-tech]

My gut says there is a LL dryer inside the AC unit... and it is plugged... take another look inside the AC unit... it will look like a bulge in the CO tube... and yeah, it is CO on the outside.

[cano]

CO tube?

[beenthere]

Copper tube.

[cano]

I looked again, I don't see anything on either copper line. I looked inside the unit around the center and also between the cage/housing part and the condenser. I see nothing. Can the line itself be clogged? Hope they don't need to replace something else.

[SBKold]

My advice is call the company and ask them to send a tech experienced in diagnosing restrictions.

[cano]

Will do. Thanks.

[cano]

Just called and let them know everything I know and he said it might be the expansion valve, does that sound right? I have my fingers crossed that it's something small and easy(read cheap, haha). Thanks again for the help.

[Shophound]

If the expansion valve was plugged, you would not see condensation on the liquid line (the "skinny line", as you refer to it) by the outdoor unit. You would see a heavily frosted indoor coil, one that would not necessarily ice up but would frost over.

You may not see the drier inside the outdoor unit if it is of the spun copper variety that some manufacturers install into their units. The spun copper driers will be the same color as all the other copper inside the condenser. The only difference is they are of a slightly wider diameter than the piping that enters and exits the drier, tapering down to the pipe diameter on each end. These spun copper driers can be tucked up into a corner of the unit where they are hard to see. But your tech should be able to find it. Just find a good tech!

[cano]

Diagnosis is that the compressor is shot. He said it grounded out. For some reason the breaker tripped which it had never done before. Then the fan was turning on when the contactor wasn't in so he checked all the wires and he said the compressor was grounding out or shorting. Also said the refrigerant was burnt.

There is a drier inside the unit on the liquid line. He said he was going to add a drier to the other line also as well as flushing the lines and something about the valve inside either being replaced or cleaned.

Does all this sound legit? The compressor will be replaced under warranty so I'm just paying labor/recharge and misc. Thanks.

[cano]

Also, I just put the outside disconnect in for a second and the fan turned on even though the thermostat is set to off. I'm just confused that this randomly happened when he was here and never happened before. Seems like a big coincidence, but I don't know much.

[SBKold]

Actually makes sense to me - the fan spinning (although usually not full speed) is a somewhat common occurrence with a grounded compressor. A tech cant really cause this to happen immediately although I bet some dishonest ones wish they could.

I feel like the compressor was coming apart - and that's what clogged up the line drier. So after he gets it all straightened out he can make sure everything is running healthy as to prevent future failures.

One thing is have him measure the amount of freon used compared to what unit calls for to make sure there isn't another restriction somewhere causing an overcharge to get required pressure/temps.

[Shophound]

Diagnosis is that the compressor is shot. He said it grounded out. For some reason the breaker tripped which it had never done before. Then the fan was turning on when the contactor wasn't in so he checked all the wires and he said the compressor was grounding out or shorting. Also said the refrigerant was burnt.

There is a drier inside the unit on the liquid line. He said he was going to add a drier to the other line also as well as flushing the lines and something about the valve inside either being replaced or cleaned.

Does all this sound legit? The compressor will be replaced under warranty so I'm just paying labor/recharge and misc. Thanks.

The tech must remove the drier inside the outdoor unit when he installs another one outside of the unit. This MUST happen, along with other crucial steps, or you will lose another compressor. What to look for to ensure compressor long life following replacement, and assuming cause of old compressor failure is found and corected:

• Burned refrigerant is removed from system and not used again
• Nitrogen flowing through piping whenever brazing operations underway
• Damp rags placed around TXV valve while brazing it in to prevent it from overheating
• Liquid line drier inside unit removed and straight piping installed in its place
• New liquid line drier installed external to the condenser
• New suction line drier installed due to compressor burnout
• After all brazing completed, system is leak tested with nitrogen/refrigerant mix and any leaks found and repaired
• Vacuum system to 500 microns or lower; system must hold this level of vacuum for at least fifteen minutes after vacuum pump is blanked off
• Refrigerant charge weighed in per factory data tag
• Refrigerant charge adjusted via superheat and subcooling readings; ideally from manufacturer's data, generic charging charts if factory data unavailable
• Indoor air filter changed, fresh, and clean, even if you changed it recently, do it again, and do it on a regular basis religiously
• Keep your outdoor unit coils clean
• Enjoy cool air

If you see any cutting of corners from the steps above, your new compressor long lifespan is at risk.

[lentz]

Glad you got it fixed. Have a cool summer.

[ga-hvac-tech]

I would add one more thing to ShopHound's list...

Blow out the lineset with a lot of Nitrogen (like 1/2 of the usual 20 cu/ft bottle). Better to get as much trash and old oil out of the lines as reasonably possible before buttoning up the system. This step would go between the first and second of SH's post.

[cano]

Thank you for all of the help. Does 7 hours sound reasonable? He originally said 4-5 hours, but the estimate says 7. Is that just there to cover himself in case of unforseen difficulties?

[LKJoel]

Thank you for all of the help. Does 7 hours sound reasonable? He originally said 4-5 hours, but the estimate says 7. Is that just there to cover himself in case of unforseen difficulties?

To do what?

[cano]

To swap out the compressor, clean out and refill the system, and replace the driers on both lines.

[cano]

It also says he's installing two isolation valves.

[cano]

???