Compressor locked on my 29 year old R-22 system. Will be getting a full new system: 4 ton R-410A, NG furnace and air handler.

My HVAC service doesn't have the right coil in stock and while waiting for a coil to arrive from the factory I began to wonder about recovery of the full charge of R-22. They cannot pump all the R-22 into the condensing unit. My refrigerant lines are about 30 ft long.

I gather the service valve can be shut off on both the high and low sides so that all the R-22 in the condensing unit is sealed in and taken away with the condensing unit. But what about the R-22 in the lines and evaporator coil? Will that just be lost to the atmosphere?

I wonder if nearly full recovery of the charge of about 12 to 14 lb could be accomplished by connecting an empty, evacuated R-22 cylinder to the service valve with the cylinder immersed in a large bucket of ice water? Would ice water be cold enough to liquefy the R-22 in the cylinder. Of course, if this is not SOP then my service wouldn't do it so I suppose this is just dreaming.


I posed this question to get opinions on what to request of the HVAC service (used them for 30 years). I will not be installing this unit myself. My current system is 3.5 tons, which worked OK for our 2050 sq ft house in the very hot climate of Dallas TX, but was marginal, ran continuously for hours in the middle of hot days. I believe that a 4 ton unit would not require larger lines. When I suggested to my proposed contractor that I needed new lines he disagreed saying he would employ a cleaning "kit". The lines are maybe 40 ft long and are not in the attic but in a chase of ca. 4 inch plastic pipe under the slab.

We are still without a/c because the air handler, furnace and evap coil are in a tight closet in our 1970 tract house. The contractor has not been able to source the 21 inch coil needed for the cramped space. He only has a 29 inch coil and this will not fit. Our current unit has an 18 inch coil, but the air handler is taller than the new one.


This 4 ton unit has been working well in the 2 yr 9 mo since it was installed. Keeping the old copper lines seems to have been OK. The unit has worked flawlessly.

The contractor first tried to pump the R-22 into a cylinder at ambient temperature and he could not get the required vacuum. I had a large bucket of ice water at the ready and carried it out. When he immersed the cylinder in the ice water the pressure rapidly went down to the required level.

2 Answers 2


The HVAC technician is required by EPA regulations to recover and recycle all the R-22 that can possibly be recovered. They should know what to do and should also have the right equipment to do it.

They will use a refrigerant recovery pump that is essentially a vacuum pump that then pumps the recovered R-22 into a tank for proper disposal.

You should not attempt this yourself as it's both dangerous and illegal.

  • I had gotten the idea that in actual practice legitimate HVAC service companies when replacing an R-22 system with a working compressor would use the compressor to pump "all" of the refrigerant charge into the condensing unit. The service valve would then be shut to seal this in the condensing unit which would be taken to a salvage yard where the refrigerant would be recovered. I thought there would be negligible R-22 remaining in the lines and coil and the tech was not required to attempt to recover that. Is this the way it is done when there is a functioning compressor? Commented Sep 4, 2020 at 2:04
  • 3
    No, the compressor is not designed to evacuate refrigerant. An HVAC technician will have an appropriate refrigerant recovery machine such as: trutechtools.com/…
    – jwh20
    Commented Sep 4, 2020 at 13:02
  • 1
    @JimStewart FWIW, that's exactly the procedure described in the service manual of my Samsung unit, so this is SOP for at least some models using R-410A (not sure if it applies at all to R-22). The procedure also requires measuring the pressure in the lines and running the compressor until that pressure drops to zero, which should ensure that practically no refrigerant is left in the lines and the evaporator.
    – TooTea
    Commented Sep 9, 2020 at 6:58
  • @jwh20 the HVAC tech recovered the full about 12 lb charge of R-22 with a vacuum pump into a cylinder. Even with the pump he had to immerse the cylinder in ice chilled water in a large bucket to get the level of recovery required. Commented Sep 15, 2020 at 3:05

A compressor burnout can mean contaminated refrigerant. This can damage any equipment you put it in. I do not have enough experience to say for certain, but I would recommend against this plan. I'm not sure if a compressor can lock up without burning up the windings, You could read up on it...

By the way, an iced tank can recover a lot of the charge; it just takes a VERY long time... It also will only recover to the vapor pressure of the ice bath, ie, not all of it. What remains will be vapor at the pressure of that refrigerant at that saturation temperature.

[Can't post as comment yet as I am new]

Mr K L

[EDIT-extended my answer to address OP comment question below about lines]

? I thought you had a new AC coming; I assumed you were having a contractor put it in? Are you doing this yourself???

Replacing R-22 with 410a system, you are going to have a new A coil and condenser. The lines are all that is left. 410a uses a different oil than R-22 and they aren't compatible. You didn't state the capacity of your old system, but the new system will possibly require different size lines. The lines have to match the system requirements or the oil won't carry back properly (compressor damage or burnout). If you reuse the old lines, they should be flushed out (labor cost,and safe flushing fluid can cost half the price of the replacement lines) Lines don't cost that much. How long are your lines?

Are you installing this yourself? This is not a job for an amateur; high pressure refrigerant is nothing to fool around with. It is also illegal, and 410a requires an addition certificate beyond 'regular' refrigeration license.

The charge also has to be adjusted to the installation.

Mr K L

  • In the course of testing the unit myself after the tech left. I tapped lightly on the side of the compressor with a hammer, and tried to start the unit. It instantly tripped the 40 A breaker in the panel. So the compressor is fully locked or shorted. Commented Sep 5, 2020 at 10:44
  • The tech had first tested the capacitor and pronounced it weak, but should not be the cause of the compressor failing to start. (I later tested it and got 45 uF and 2.4 uF. It is labeled 45/5.) He then put his current clamp which registered 107 A and immediately tripped the compressor internal breaker but not the breaker in the panel. Then a couple of days later when I tried to start it the breaker in my panel tripped. Commented Sep 5, 2020 at 11:54
  • Do I need new copper refrigerant lines? We have been without a/c for 8 days now, no fun! Commented Sep 8, 2020 at 12:52
  • Edited my question to respond to edited answer of @troubleshooter. Now 9 days w/o a/c. Tonight my wife ordered an 8000 btu/h window unit for one room. Commented Sep 9, 2020 at 7:55
  • Finally got new a/c installed today. Fourteen days in Dallas TX heat was not fun. The installing company had trouble sourcing the specific 4 ton evaporator coil needed in the tight closet in our 1970 tract house. We did have an 8000 btu/h window unit for the last two nights which made all the difference for sleep. Commented Sep 15, 2020 at 2:52

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