Central Air EVAP coil froze solid

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AC wasn't cooling house well so I called the man. First he found the refrigerant low. Checked the evap coil and it was solid ice. Had to let it thaw and he came back and put about a pound of 410a in it. All good now!
 

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Also, to prevent evap coil freeze be sure the the air-flow is good such as clean air filter, and nothing blocking air intake vent and exit vent. People often make sure the exit vents are not blocked, but will place stuff blocking the air intake vents without thinking about it or realizing that also drastically reduces air flow.

If the furnace has a humidifier be sure its water source is shut off 100%. Sometimes the water line is a 1/4 inch line that was added with a tap, and just tightening down the tap will not block the flow 100%.
 
Also, to prevent evap coil freeze be sure the the air-flow is good such as clean air filter, and nothing blocking air intake vent and exit vent. People often make sure the exit vents are not blocked, but will place stuff blocking the air intake vents without thinking about it or realizing that also drastically reduces air flow.

If the furnace has a humidifier be sure its water source is shut off 100%. Sometimes the water line is a 1/4 inch line that was added with a tap, and just tightening down the tap will not block the flow 100%.
Interesting you say that. I had forgotten to turn the humidifier off and the water off.
The air filter was clean and condenser clean.
 
Ummmm... how about the expansion valve?
From what I remember bad expansion valve causes the coils to freeze up.
I would rather that, easy replacement, than a leak!
 
but he still was a pound low on freon...it had to escape some how...
I hope it’s all good for the OP.
I was curious as 1 LB doesn’t seem like a lot to me for coils to freeze in a central air unit but what do I know?
Depending on the technician I just feel like anybody can squeeze an extra pound into a system, even more. But I’m sure I’m wrong or better said I was just curious
 
I hope it’s all good for the OP.
I was curious as 1 LB doesn’t seem like a lot to me for coils to freeze in a central air unit but what do I know?
Depending on the technician I just feel like anybody can squeeze an extra pound into a system, even more. But I’m sure I’m wrong or better said I was just curious
The newer systems don’t take a whole lot. My system only takes ~3lbs 12oz, cramming more in there will result in worse performance.

I’ve been on a HVAC kick lately… I know just enough to be incredibly dangerous when it comes to AC (I still don’t quite understand subcooling and superheat, I just know they’re important), which is why I don’t mess with anything beyond replacing control boards or capacitors lol
 
The newer systems don’t take a whole lot. My system only takes ~3lbs 12oz, cramming more in there will result in worse performance.

I’ve been on a HVAC kick lately… I know just enough to be incredibly dangerous when it comes to AC (I still don’t quite understand subcooling and superheat, I just know they’re important), which is why I don’t mess with anything beyond replacing control boards or capacitors lol
Yup! :Last week of April. New Condenser fan and capacitor on one of the units.
I also bought my own gauges and freon (many years ago) after 6 or 8 years of so so cooling on the main level/incompetent service people and charged the unit myself, been perfect since then. They were using the wrong pressures not knowing this unit was dual freon capable. I did many years ago as a precaution have them replace the expansion valve but they still got the pressures wrong. (unbelievable, I think they just wanted to sell me a new system, it happens A LOT around here)

I used OEM parts for the new fan and capacitor, believe it or not, this unit was serviced about 6 years ago by another incompetent well known AC company to replace the fan and capacitor but they used a cheap universal one (black one in photo) and it started making bearing noise 1 or 2 years later... this year, it REALLY went bad so I replaced with the OEM motor.
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Also replaced the capacitor (came with the OEM fan) Picture is old one put in by incompetent service person years ago.
16 years old now two units still working perfect, just these very few items replaced and if done right the first time would not have needed the second fan or freon.
 
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I mean it is Michigan, it might have 20 more years left in it!

Ours is 17-1/2. Still running strong! (Fingers crossed).
Interesting thing.
When the manufacturers started testing the new freons, they had issues getting the old mineral oil to return to the compressor.

The newer freons have compressors with synthetic oil (PAG).
Side benefit is they last longer.

How's that for turning this back into a BITOG thread!!!!
 
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