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nxhappy

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need some home AC help. guy came out ....could not find anything wrong. pressure levels OK. everything OK. during the really hot days AC just quits. being fed up I installed new capacitor. first boot up, ran for about 10 minutes, then fan stopped. Also the fan is only 1-2 years old. as of now AC is running. I believe compressor is from 2010-2011. thermostat clicks so i think it's ok. so WTF is going on ? fan is newer, freon level good, capacitor is brand new. Filters are somewhat new. PS it's 116 today.
 

SVTdreamin04

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What do you mean by the AC just quits? We will start with the very basics on this list.

1. Is the compressor running?
2. Is your condenser coil clean?
3. What were your pressures? High side and low side when they were checked and what was the outside temp?
4. When the AC is running, is the compressor short cycling? Or does it running continually?


I really need to know what type of refrigerant your system is and what the pressures were when the service guy checked it to be of more help.


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SVTdreamin04

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As outside temperature goes up, your pressure will drive up as well. Your condenser may not be able to shake off the temperatures of 116 degrees. Also, your condenser fan could be false tripping on the thermal overload from the excess heat of 116 F.


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john11gt

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A lot of words and no real information in that post.

going off that info and not feeling like walking you through it step by step I’ll take a shot in the dark and say, remove the top of the condenser and hose out and clean the coil. It might be going off on a high pressure cut out on the real hot days.
 

SVTdreamin04

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Capacitor can be tested with an meter along with the motor.

Can you get a gauge set and monitor the pressures yourself while the unit is running? I would assume when the guy was out, the u it was running fine so he was never able to see the issue as it happened.


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xblitzkriegx

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If you had a guy come out and he didn't find anything, I'd ask for my money back.

The questions being asked and some advice given is exactly what the tech should have done.

HVAC isn't that hard on residential units
 

SVTdreamin04

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My guess is a high pressure problem. Hard to say without being there and seeing what it is doing.

High pressure due to 116 degree heat. See it all the time. Only on systems that hold much much more refrigerant.


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ShelbyGT5HUN

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I had this exact problem! The condenser fan, would randomly turn off, yet the compressor would run. Thermostat clicked, all freon levels good. Completely random failures. It could run fine for days, then just stop.

As a guess I inspected the "AC quick disconnect pull out". It was VERY LOOSE, and slightly corroded. Lightly wiggling it would cause the fan to stop.

I re-bent the tabs for a more secure fit, and wire brushed the contacts, then cleaned with electrical contact cleaner. Fixed it! Ran flawlessly for the next 4 years, until we moved.


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ZOMBEAST

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If the fan stops but the compressor continues to run for a short time (until high pressure refrigerant switch shuts it down), I would focus on the fan. It could be failing. Did the tech check the amp draw on the fan or compressor? It's possible you have the wrong size capacitor, or the recently replaced fan was not the correct hp, or when replaced the blade or motor was not positioned at the right height and not pulling enough air across the coil. Also, as previously mentioned above, make sure coil is clean. If both the fan and compressor shut down at the same time, it's likely the high pressure switch tripped. It could still be the fan not pulling enough air.
 
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beau t

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I basically had the same issue, had a guy come out and check it Freon was low he added Freon and we found the A coils were leaking so we replaced them it ran for about a day and stopped again. I went out to the unit to inspect and the display said it had a high pressure alarm??? Upon looking around I found the high pressure switch wires had rubbed against the coil of copper hose going to the switch and rubbed through it giving it a false signal attaching pic of wire look at the top side of the wiring and you will see where it arched - - check for things like this - - purplish colored wire just as it goes pass the compressor about half way up on the pic
 

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wizbangdoodle

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Full System(Air Handler, Condenser) 3ton variable speed American Standard, like 14k. I’m in the process of shopping for bids.
I was quoted $24k for 3 mini splits and a single condenser. Total of 45k BTU's. Looked online and found the equipment for about $6k.

Signatures are for pus... oh, wait...
 

03cobra#694

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Full System(Air Handler, Condenser) 3ton variable speed American Standard, like 14k. I’m in the process of shopping for bids.
Mine was just a tick under $9,300. 4 ton Trane, VS inside and out. The T-stat is crazy. I have pictures in my "New Driveway" thread. What kind of heat, electric?
 

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