LG window AC not cooling

I have an LG window type air conditioner 18.5 kbtu model LWHD1800R. This unit was purchased 06/09/08. In 07/26/10 a new compressor was ordered and replaced under warranty. On 07/22/11 LG was contacted again about the AC not cooling properly. When the outside temperature reached the mid 90's the AC would quit cooling. I was told to contact a repair service company but I could never get in touch with them. on 07/28/11 the LG tech came and looked at the AC. At this time I had removed the AC from the home. The Tech plugged the unit into an outside receptacle. The outside temp was 85 degrees. He watched it cool for about 5 minutes and declared it operational. When I told him that the unit was not going to operate when the outside temp reached 95+ degrees his response was tha the unit wasn't designed to operate at those high temperatures. When I called the company to complain their response was that the unit was operating at it's designed specifications. This unit has another 4 years of warranty left. Bottom line...the unit will not cool on hot days and it is useless.

What could be the cause of this unit kicking off on hot days? I had to replace the unit with a Frigidaire, also 18.5 kbtu, which cooled with no problem.

C.B.38, did the tech actually take readings like current draw or air on/off the cooling side. would have been helpful to have pressure readings as well. Thinking that if A/C runs fine then spits the dummy at 95F or 36 ish degrees C than system is overcharged and cuts out compressor from high discharge pressures. This is easily fixed by Qualified person should this be the case.. Mike. PS. Window shakers, (box a/c's) can run in temperatures in excess of 100F.

All he did was put his hand in front of the discharge air and then put his hand on the copper line, which was hot, and he said that if it was hot it was cooling OK. This was from the factory LG repairman.

Could he have forced the AC into a simulated 100 degree condition, like blocking off the input air or disconnecting the fan?

Thanks for the info.

Blocked condensing coil most likely. The outside is fine, but if you look in from the fan side the bare copper piping with the sludge of the fins will be visible. You can clean it from the outside with a hosepipe and a jet nozzle ( not a high pressure cleaner, that will remove all the fins it does not bend into pretzels) until the little flakes of aluminium stop coming out of the drain hole. Caused by the drain bung still being in the unit, and by the thin plate the coils are made from.

Believe it or not those coils are available as a spare part from LG ( at least they are here, in South Africa) and are easy to replace, provided that you are willing to spend the money on a unit that is that old. A recommendation on the new coil or unit is to either get a coated coil - Carrier and others have that as an option, or spray the new coil with a anti corrosion coating before first use, available from Carrier on my side. That does help a lot to prevent the coil blocking, but they must be washed at least every 6 months to keep them clean, and the coating reapplied. I still have a single one of those 18000 BTU coils, the unit it was destined for died from a leak in the evaporator that was not economical to repair, compressor was very elderly and close to rusting through at that point, though the condenser was still going great, it only being a year old.

I don't think that is the problem. The unit is very clean inside. It sounds as if it was overcharged when the compressor was replaced last year, as you stated in your first reply.

Just wash outdoor coil with water from hose and after 24 hours see if it is going to cool now.
If not, you have possible refrigerant leak and unit is kicking off on compressor internal thermal protection.

What type of compressor is in the machine. Rotary compressors generally run hotter than others, and combine the high ambient temps with the possibility of an undercharge, the compressor goes out on thermal protection.

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Originally Posted by nike123

Just wash outdoor coil with water from hose and after 24 hours see if it is going to cool now.
If not, you have possible refrigerant leak and unit is kicking off on compressor internal thermal protection.

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The coils are very clean.

I do not know for sure but I do not believe it is a rotary compressor.

O.k. Simple exercise with a/c out of its housing to expose compressor and pipework. If air-conditioner is still out of its normal location within your house then, with a cardboard box (that is big enough to cover the vent where the chilled air comes out, and where the air is drawn in to be cooled), place this maybe 6 inches infront so as to let around half of the chilled air to escape, then set a/c to coldest setting and fan to medium speed and turn on a/c. Now, on the compressor, there is two copper pipes that run off in different directions. The larger one, before it attaches to the bottom of compressor, will run into a large black cyllinder. ( Got to wing it now;)). Run a/c on cool for a few minutes to let compressor warm up and make sure not all the cold air is going back into a/c or it will stop on thermostat. What i am looking for is the large copper line going to this cyllinder to start to sweat, depending on humidity, but it should be cold to touch, not frosted. There are several variables that can mess this up. One, try to avoid the rejected chilled air from being sucked into the condenser on the back of a/c, and two, not enough or too much chilled air is returned to be cooled. let us know how it goes.. Mike... PS. For everyone else, bite me! :p

Mike, The AC has been moved to another location. It is obvious from the above responses that the so-called LG Service Person did not know what he was doing or was too lazy to fully test the unit. Anyway, LG is not going to honor the other 4 years of the warranty. I really appreciate everyone’s help.

I am going to send this information up the line to LG, with a copy to Home Depot, (from where I purchased the unit) and a copy to the state Consumer Protection Agency.

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Originally Posted by Country Boy 38

Mike, The AC has been moved to another location. It is obvious from the above responses that the so-called LG Service Person did not know what he was doing or was too lazy to fully test the unit. Anyway, LG is not going to honor the other 4 years of the warranty. I really appreciate everyone’s help.

I am going to send this information up the line to LG, with a copy to Home Depot, (from where I purchased the unit) and a copy to the state Consumer Protection Agency.

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C.B.38, You might want to read the legal details regarding the use of information from this site. Just a thought..Mike.

Mike, I will consider the legal details. Is it not OK to use the information from this site. I do not want to do anything wrong. Do you object to my using your information? Would it be proper to not quote this site but to state that the opinions of other professionals is .................etc?

Bill

Quote:

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Originally Posted by Country Boy 38

Mike, I will consider the legal details. Is it not OK to use the information from this site. I do not want to do anything wrong. Do you object to my using your information? Would it be proper to not quote this site but to state that the opinions of other professionals is .................etc?

Bill

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hi there Bill. I don't have a problem with you using information i've posted, but go to the bottom of this page and read the fine print in the green section. To ask permission, i'd go to " FORUM" then under the "legal" heading, post your request, or private message one of the moderators... Yes, you can state the opinions of professionals. Hope you are able to get your warranty straightened out. All the best, Mike.