I'm having problems with my LG 25.5 K BTU window AC.

[Lammy]

I'm having problems with my LG 25.5 K BTU window AC.
I turned on the AC when the lights came on this morning, but the fan inside of the AC does not turn on. The AC is an LG. just over a 2 ton. 25,500 BTU i believe. 220 volt.

if anyone has any troubleshooting ideas for me I would appreciate it.

I've had the large window AC installed in the attic above my garden for about a year and a half. the attic is well vented near the AC and it's rather cold outside (20-30°f). I've heard that some AC's need a low ambient temperature kit. but I used mine all last winter in the same capacity with no problems. plus I have a similar model that I'm using that is actually in a window and is working with no problems.

I have a co2 burner hanging underneath the AC so that normally the hot air from the burner rises up to the AC and is instantly cooled to a reasonable level and blown into the garden area. but while the lights were off I had the AC turned off and was using the CO 2 burner plugged into a thermostat to heat the room. I hope that did not somehow overheat the AC. I would think it should not have been a problem because I still had some circulation fans running and I was only heating the room to about 65 degrees Fahrenheit. however all the heat from the burner would have went straight up to the niche in the ceiling were the AC is installed. but it's not like it started to melt or anything.

it seems that I can hear the fan trying to spin but it sounds like its under powered. I tried turning off most of my lights. I ran a new wire to the AC off of a different breaker to test the wiring. I also tried banging on the face of it a couple times. all to no avail. I've switched different modes and settings on the AC to make sure the fans is suppose to kick on and indeed I can hear it try. all my circulation fans an inline fans are still working.

anyway I'm really tired and the attic is hard to get to, to access the AC so I thought I would ask if anybody had any troubleshooting ideas and I'll try and take care of it a little later.

thanks in advance for your time.
Lammy

 

[eyes]

slide the unit out of the chassis and get a ohm meter. disconnect the fan wires and(if you can) and check to see if there is continutiy. also, see what the fan is rated for probably 12- 24 volts. take the 2 wires coming off the fan and run power to those with 12- 24 volts only) through battery or tranformer rated correctly. if the fan runs, then its something possibly on the circuit board? a capicitor? maybe. hopefully just a bad fan and not board.

 

[Lammy]

thanks for the reply eyes.
I'll have to get some help to get the AC down so I can try that.

 

[eyes]

no.problem. ill be curious as to what it is.

 

[Lammy]

eyes
I guess the problem was that the fan was literally frozen. it had ice on it.
I originally did not think that was the case because it was above freezing outside and I didn't have a problem with it when it was below freezing.

I never made it into the attic to look at the AC. but what I believe happened was that: I started turning the AC off during the dark cycle when it wasn't needed, which allowed the normally warmer AC to cool down and also for the fan to be stopped for a while. which allowed condensation to freeze it. the outside temp needed to stay a bit above freezing for awhile for it to thaw out.

the solution was to just keep it running all the time or at least to put it into energy saver mode during the dark period So that it still kicks on every 10 minutes and prevents it from freezing. I also installed a high powered vent fan to blow in air from outside. plugged in to a over temperature sensor. this way I have no down time.

I hope this information helps somebody else.

 

[PrivateAero]

If you turn the ac to fan only it'll stop it from freezing. I have bought several 24,500 LG and run them in the winter. My ac buddy says the oil gets to cold and it fries the condenser but after a winter or two the condenser starts making crazy noise and ya need another 600 bucks to replace it.

Privateaero

 

[Lammy]

Thanks privateaero. I actually never even considered using fan mode I was turning it off at night because it would drop the temp down to 60.

I've considered hooking the LG up to a relay so I can use it with a cap thermostat and put that remote temperature sensor right into the canopy. because of the awkward placement of the AC's they tend to not control the temperature perfectly.

the LG AC says that is not to be used on a timer and I'm worried I might shorten the AC's life quickly by switching it on and off via the power supply/relay. you wouldn't happen to know anything about that would you?

I was thinking about pulling the temperature sensor out of the grill of the AC and wrapping it with a small light bulb in aluminum foil. and connect the small light bulb to the thermostatic relay in the hopes that when the thermostatic relay kicks on it will heat the sensor for the AC and ensure that the AC does indeed kick on, and if that happened to work, I think to make it extra badass, I would put some extra circulation fans that would kick on with the AC.

 

[PrivateAero]

excellent proposition. I'm currently tackling that problem as well. I was going to cut the wire for the thermostat and control it with a relay. I checked a 5k unit and it just supplies 120v when the thermostat gets hot. I'm thinking the 24,500 might be analog since it seems to kick the fan up higher when the room is farther from set point.
I have a lot of other upgrades I have to do right now but come early march I'll revisit this problem.

https://www.icmag.com/ic/showthread.php?t=255468

Privateaero

 

[Lammy]

aero. I think I've got it!!

this is my idea: the bulb wrapped with aluminum foil with the temperature sensor for the AC, let's call that heating element.

okay so if you weren't worried about your AC over cooling as my attic installed unit tends to do. ( but my window unit under cools) then you could use that cap thermostatic relay to control only the heating element. I think that would help with the issue someone brought up in your thread about the AC trying to tailor its power usage to the load on it. you can leave the heating element and temperature sensor in the AC grill so that it acts like normal but then when your temperature relay kicks on it will know that it needs to kick it into high gear.

now the other issue. over cooling and my fear that if I use the power supply to switch the AC on and off often then I will hasten its demise. my solution to this is to use a second thermostatic relay which will need to control a heavy duty relay-contactor to operate the AC.

so if you wanted to hold the canopy temperature at approximately 74 degrees. you would set the thermostatic relay ( for the heating element) too cool to 74 and the AC thermostatic relay to shut off below 68-70 to prevent over cooling.

I think all of that should work pretty well without interfering with the air conditioner too much.

I can't take credit for the bulb in the temperature sensor idea as I saw that around here. someone using it to do a DIY chiller.

 

[Lammy]

well a couple issues I just realized.

if I use the relay to turn the AC off to keep it from over cooling. it may freeze up again. however I think that might have been caused by the heat from the CO 2 burner warming up the chassis of the AC which was in freezing weather causing condensation and freezing.

if I'm not mistaken when you kill the power supply to the LG AC's they reset the temperature setting to 74 or some factory preset. so depending on the thermal dynamics of your setup that might make it pretty hard to run the room at a higher temperature than the factory default.

 

[PrivateAero]

Great idea. How about we set the ac to 80 so we never have to worry about it over cooling. Then the heading element will keep the temp where it belongs. Any ideas for the heating element?

Privateaero

 

[PrivateAero]

do you have problems with it over cooling sometimes?

Privateaero

 

[Lammy]

do you have problems with it over cooling sometimes?
Privateaero

yes every time the lights go out it drops the temp to about 58 to 60 degrees while it is set to about 74 or 75. but really the problem is everytime the number of kw's I'm using changes. with my attic installed AC if I kept running the same number of lights and the outside temperature remains approximately the same the AC would be really good about holding a set temperature.

the window / wall mounted unit is another story. since it is not at the highest part of the room it often reads cooler air. a remote sensor would be the perfect fix for that

Great idea. How about we set the ac to 80 so we never have to worry about it over cooling. Then the heading element will keep the temp where it belongs. Any ideas for the heating element?

Privateaero

Aero you just saved me like 100 dollars. thank you.

the heating element is simple and cheap (i hope) the smallest incandescent light bulb I can find. wrapped in aluminum foil with the temperature sensor from the AC. plugged into the thermostatic relay.

the aluminum foil will keep all the light contained but still allow heat to be transmitted. hopefully all that can still fit in the grill the AC so it can work as intended most of the time.