Window AC - Bad Cap, Cutoff, or is Compressor Toast?

3 years ago

I'm hoping someone with repair knowledge can offer some input on a inoperable Window AC unit.

Quick version. 2 year old 10,000 BTU Kenmore (apparent LG Components) has full power and working fan, but the compressor will not engage. A video of the symptoms is here: https://vimeo.com/419645674

Does it seem like it's simply a bad capacitor, maybe a bad thermal cutoff switch, or is this symptomatic of a dead compressor?

More detail: Unit is a Kenmore Elite 77101. It was just over a year old and hadn't even been through 2 summers yet when the problem started

Symptoms: Full power and apparent function - Fan runs and the panel acts like it's working properly, but compressor will not engage. There's a very faint "tick" sound (relay?) and what seems to be a change in power level to the fan for a few seconds, then the the fan resumes full power (in the video you can even see the fan speed change as the compressor tries to engage) I'm assuming this is the start relay trying to engage the compressor, but when it can't it stops trying.

I have tried a suggested technique of tapping the compressor with a rubber mallet as it tries to engage with no effect.

There were no issues leading up to this. No freezing. No drop in output, no odd noises, no apparent cycling issues. Just a sudden realization that the room was hot and that the compressor wasn't on. It had been hot the few days before it stopped working, high 80's to low 90's with high humidity, but nothing it hadn't handled before.

In general the unit was not overworked though. I'd even kept the thermostat set at 78 to keep power use down and to keep from over working the unit. We would usually turn it to just fan at night and open windows when it cools down, but it had been on the cool setting for over a full 48 hours. Even that doesn't seem like it should stress the unit that much though.

We tried power cycling, and even left it unplugged overnight with no change.

I'm trying to decide if it can be reasonable repaired, or if I need to look for a replacement before it starts getting unbearably hot (in either case, I don't think I'll ever buy Kenmore or LG anything again).

Any input is greatly appreciated. THANKS!

Sort by:Oldest

Comments (5)

dadoes
3 years ago
Could be a bad capacitor. Could be a locked compressor. Could be a wire burned off. Maybe a bad start relay.

Not a bad thermal cutoff ... that's what's repeatedly shutting off the compressor (and on when it cools sufficiently) from trying and failing to run.

The fan slows during the start attempts due to overall increased current draw and amperage draw.

77101 is not a full model number. The correct number is on a model/serial label affixed somewhere on the unit. Probably syntax of xxx.xxxxxxxxx (three digits, a period, and more digits/characters).
K. Black thanked dadoes
K. Black
Original Author
3 years ago
last modified: 3 years ago
Dadoes, thanks for the reply. The full model number seems to be 580.77107710. I'll have to get to the box later to confirm.

After looking at parts numbers and comparing the control layouts, I'm pretty certain that the Kenmore is actually a re-badged LG Model LW1017ERSM. Same slide out chassis. Same remote.

Sadly, a significant number of the 2 and 3 star amazon reviews (21%) mention a similar, if not identical issue. Maybe now that I know a more widely sold identical model. maybe I can manage to better narrow down a fix.

I'll have to open the box up again to check the part number, but capacitors only tend to be around $35-$40 from what I can tell. Maybe I'll give that a shot. On the other hand, from what people are describing it doesn't sound promising, so maybe that's $40 better put toward a different brand that won't maybe just fail again in a year.
Related Discussions
3T Bryant / Ruud HP advice request
Q
Comments (18)
An update: I need some more advice I did go ahead and buy the 3T RUUD unit last year as guided. It has worked very well and I got the tax credit too. A/C worked well last summer however this past winter we had a reasonably cold February here in Houston. The HP did have to "work" long cycles to get the area somewhat warm. I am concerned about the unit having to really work long cycles and produce not really warm air. Is running a lot - to warm the space... The performance seemed to be much better when the temperature went to 40F during the day when the units would kick on. During the coldest part of the snap it struggled to get adequate heat into the space. The last heat strip units ran 25 years and did a good job, however much more expensively. Going forward I is trying being as efficient as I can be. I have a second unit to replace...I nursed that old 2nd Lennox HS unit thru this past year and don't believe it will last at all this season. I recognize that I have another unit to buy and the HP did save $$ on the heat and A/C side this year. Markedly... Besides Texas still have funds left for rebates on efficient units. Want to get that B 4 it runs out. So I need to act. Since I am all electric (NO Natural Gas), I am looking for another unit at 2.5T for this other side of the home. Manual J says 2.5T is needed. The rooms in this living area are the sleeping quarters, bathrooms, master BR and showers along with the den. I need to make sure that the heating aspect will provide more heat than what I experienced with the 3T heat pump in the main room this past winter.... I need to feel warm in the winter in this other space since there is a risk of catching cold / other by stepping out of the shower. if the heat is not present in qty. AND another consideration - when we get up to go to work its usually in the early AM, when the temps are most likely to be at the lowest part of the day and the HP will probably be the least efficient that is when the heat is needed. I need to address this aspect in the choice I make today... Contractor who did the last install did a good job... I have no issue on getting another RUUD and using him He is quoting another RUUD 2.5T HP similar setup as last year's 3T HP UPQL-030JEZ AH RHKL-HM3617JA 7.5KW HS 15.5 SEER / 13 EER New supply and return Plenums 5" Pleated Filter System New Copper Lineset Crane for roof Top Mounting $7,000 installed to code If I look at the RUUD website, the unit is not rated as an energy credit qualifying unit. In addition the warranty that is published ion that unit is only 5 years as the warranty on the other units is 10years. The last units I had that were HS Lenox units lasted 25 years. I want to make a wise investment so the unit I will buy is a solid sturdy unit that can last a very long stretch.. 5 yr stated warranty seems light to me.. Can you give me some insight on the unit quoted..?and some suggestions on what other Ruud units might be "A Step Up" and sturdier and a "value". Manufacturers update lines all the time. Maybe further improvements were made on some Ruud units ..AND - Maybe he is quoting a good solid workhorse unit and that's fine.. A good solid unit is what I want. Increase HS capacity to what level? Can the other unit be retrofitted w additional heat capacity? Vertical Vs Horizontal AHRI Data will be a great help on your suggestions. Thank you in advance...
...See More
Window AC not cooling properly
Q
Comments (6)
We are having the same problem with our older "WallMaster" unit by Friedrich. After cleaning both coils, filters, checking thermostat, etc finally broke down and called in a repair person. Sad news was that the compressor is going causing the unit to shut down before reaching the proper temperature. Try all the above suggestions, especially cleaning the filter, and a through cleaning of the units coils (both). Get a good thermometer (an instant read kitchen one will do), and check the difference between the incoming air (front of the unit), and what is being blown out. There should be at least a 12-20 degree difference. If the condenser comes on, but shuts down after about 10 minutes, you may have a problem with motor (condenser), in which case it would be cheaper to chuck the unit and buy new. In fact considering how inexpensive units can be,you may wish to look into getting a new one sooner rather than later. The last thing you want to do is purchase a new unit during a heat wave because your current AC died a slow painful death. If funds are tight check Craigslist for local people selling units. They may not be what you want, but it will get you through the summer, that way you can wait and get a good deal when stores are clearing stock in the late Fall.
...See More
Need help with HVAC decision
Q
Comments (9)
If you are buying Carrier equipment, then it is best to buy from a factory authorized dealer. They are supposed to install the equipment to your satisfaction or remove it and refund your money. They should also have better training than the typical Carrier dealer. The Comfort series is Carrier's entry level product. I would be a good idea to upgrade to the Performance equipment. It is a little better built and quieter. I think upgrading to the 2-stage Infinity furnace is expensive, but worth the money in my opinion. I hope your upgrade price includes the Infinity controller. The ECM motor is reliable, but is expensive to replace if it ever goes bad. If you get a labor warranty get it through Carrier. I have the Carrier warranty and I am not forced to have maintenance. But you do have to take care of your equipment and not abuse it. I suggest having maintenance done once a year. You should not pay more than 10% of the total price for the labor warranty. You are already covered by a 10 year parts warranty.
...See More
Carrier Infinity Compressor life expectancy?
Q
Comments (35)
Our 25HNA Carrier is on its THIRD compressor (first one failed, a second died this spring) and now we have an issue with the TXV valve. At this moment the tech is attempting to recover the valve by using some special substance that has worked "wonders" he says, to a pattern of problems with the original issue of failed compressors. He says that the refrigerant systems is meant to be sealed and that once it is cut to replace a compressor or TXV valve, it ramps up the possibility that contamination can enter the system. Between issues from faulty Bristol two-stage compressors, to those Copeland units which had a lubricant that clogged the system using the R410A refrigerant, and the openings/closings of sealed coolant lines, what does one expect? Once that happens, he says, it's IMPOSSIBLE to completely reverse that. I'm being penny wise/pound foolish as I'm paying up to $700 to attempt to cure or replace the valve (he is installing some kind of additive), but the alternative to the short term gamble, is DITCHING the unit (7 years old) and getting another $8,000 unit for a home we plan on leaving in the next two years. I'm investigating at this time whether it's possible to go for small claims ($5K cap in my state) at this stage, and perhaps the attorneys would rather settle than come to court. This kind of pattern of failure is amazing, my tech says, and I'm seeing this all over the HVAC forums here. Surprising that this hasn't yet been swept up and slathered all over the mainstream media, as it seems the big companies are trying to keep it swept under the rug.
...See More
kevinande
3 years ago
Window units are not exactly designed to be worked on, especially in the modern world of throw away appliances. Some may disagree with me, but given their cost it makes far more sense to simply replace it unless you just want to tinker with it. Certainly hiring someone to do the work is not worth the cost. Back when I was a young whipper snapper we had three units in our country home that were all 220V and they lasted for years. I seen to remember my dad complaining a lot about the electric invoice too lol.
K. Black thanked kevinande
dadoes
3 years ago
Surprising ... the model number does search at SearsPartsDirect.com.

They list the capacitor at $26.95. Possibly can find it for less. And perhaps better to shop parts elsewhere, Sears is notorious for advising *after* placing an order that items are out-of-stock/backordered or even NLA.

It's a combination start/run compressor/fan capacitor. Can't quite read all of the rating info, the item photo has it turned to the right. But, 270VAC, 50/6.0 uF ... something, something, etc. Match whatever's on the original.

Capacitors can be tested with a meter if you have one and know how. Also can visually examine if it appears "swollen," burned, or the vent cap is blown.
K. Black thanked dadoes
K. Black
Original Author
3 years ago
" It's a combination start/run compressor/fan capacitor" -- Ahhh, That explains it. I could only find a fan start capacitor on the LG site.

" Capacitors can be tested with a meter if you have one and know how ". I do have a good Fluke multi, watched a few videos, and I'd toyed with the idea of testing it as I was putting it away for the winter, but I haven't messed with high voltage Caps before and didn't have a way to safely discharge it. I'm wondering if it will still have a significant charge after 7+ months. I can make a discharge tool, but that also entails extra cost, even if I'm just buying heavy gauge wire and figuring out what size resistor to use.

I didn't find any scorching or signs anything was blown, as I recall. No telltale swelling either, but it may have been in a sleeve that I didn't feel comfortable messing with at the time.

Window AC - Bad Cap, Cutoff, or is Compressor Toast?

Comments (5)

dadoes

K. Black
Original Author

Related Discussions

kevinande

dadoes

K. Black
Original Author

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

Window AC - Bad Cap, Cutoff, or is Compressor Toast?

Comments (5)

dadoes

K. BlackOriginal Author

Related Discussions

kevinande

dadoes

K. BlackOriginal Author

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

K. Black
Original Author

K. Black
Original Author