HVAC evaporator freezes, I tried everything, what next?

>>1026122
This Old House just covered that a few weeks ago, in that particular case the HVAC was oversized (too powerful) and had to be replaced.

Chek on youtube, that's where I saw it.

>>1026123
Yeah ... my house is from 1984 but the HVAC is from 2009
I bought the house last year but the previous owner died and his estate lawyer sold the house
This means I have no information about past problems (which should have had enough time to be seen)
I'll have to check the outside unit and compare to the size of the house and see if that's the case.
Then I'll probably have to get a more powerful fan (if possible).
I like cold and getting a SMALLER system is the last thing I'll do

>>1026122
A frozen evaporator coil means that its getting too cold.

Oversized units that dont get enough airflow over them can do this.

Appropriately sized units with obstructed airflow either in the supply side, or a malfunctioning blower.

Or the unit is low on refrigerant and the low pressure side is too low in pressure.

Call an HVAC guy and tell them your evaporator is freezing over. Common problem

>>1026122
possible causes
Lack of airflow
Loss of charge(low refrigerant)
Issue with the metering device. (plugged orifice or non-functioning TXV)
Over-sized system
System running for extended periods at to low of a return air temperature.

if the system was "properly" serviced most of these issues would be apparent to the technician.

>properly

>>1026136
>>1026138
the unit was inspected a few weeks ago and it passed (according to the technician)
Said technician, however, didn't seem to know a lot about HVACs systems in general and my system in particular (he told me this is the last year I'm covered by the manufacturer's warranty when the system is still covered until 2019 among many others).
The only thing he actually did (beside just looking at easily accessible stuff) was to measure the refrigerant but I wasn't paying attention (my fault, I know) and I can't say for sure if the numbers he got were the right ones.
Before calling anyone (to fix it) I want to make sure I'll do whatever I can to find the problem myself.
I'll start with researching the outside unit's power and compare it to the house.
Then look into more powerful fans.

How hard (and expensive) is to check the coolant myself?

>>1026138
also, how do I check the TXV?

>>1026139
>System running for extended periods at to low of a return air temperature.
One thing you can by yourself do is put a thermometer on the return side and measure the air temp. If it gets down to 65-68 and runs for long periods of time(hours) the coil could freeze. But for some reason I doubt this is your problem.

>Over-sized system
If you know house square footage and system tonnage can give you a rough idea but to determine for sure you will need to do a proper load calculation/call someone

>Lack of airflow
Will need to measure with proper metering tools/call someone

>Loss of charge
Will need system pressures, temperatures and possibly electrical readings to determine. Requires specific tools and knowledge/call someone

>Issue with metering device
:see loss of charge

>>1026139
It was inspected by someone who didnt seem to know about HVAC?

Dude. Call a real hvac guy and have them come out.

Unless you have the equipment you cant do shit with the refrigerant, and throwing money at it without knowing whats wrong is the epitome of stupidity.

Find a local HVAC guy who runs his own shop and has been in business for ten years or more. Those guys stay in business because of word of mouth, not advertising.

>src: landlord with over 80 individual properties, 3 free standing apartment buildings, and manager of a privately owned complex.
DONT THROW MONEY AT AN UNKNOWN PROBLEM.

>>1026153
I'll get home later today and I'll post some numbers
>>1026158
That's the whole idea of posting here first (after reading stuff on internet and doing the most simple/cheap stuff first like changing filters, cleaning the evaporator etc etc).
I find it really intimidating to call someone for a problem without (me) knowing at least something about that problem.
Now, the question is:
How do I find a local guy with his own shop without relying on advertisements?
Everyone I know just calls the number on the card that was left on the HVAC by the last guy there.

>>1026164
>How do I find a local guy with his own shop without relying on advertisements?
Ask around.

and you've already done the diy cheap stuff. time to make a call

>>1026122
Turn it off. let it melt, turn it back on.

OP here
outside unit:
Rheem RANL-042JAZ - Classic Series 3 1/2 Ton
13 SEER, R410A Air Conditioner Condenser 208-230 V, 1 Ph, 60 Hz
House is 2148 square feet
good insulation in the attic
decent windows
the thermostat is set for 82 during the day and 72 evening/night/morning
outside it's been around 80 lately


is it oversized?

should be good.
time to call someone.

Better business bureaus should be a good place to start. Find a company that's been around for 10+ years and consistent good reviews and review followups.

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OP here.
I called the company that did the inspection a month ago and they'll send someone this afternoon in a so called "warranty call". At least the diagnosis will be free.
Thanks for all the advice and I'll (try to) keep you updated on the situation.

>>1026403
I'll do that if nothing's solved today.
Or if they want too much money.

Technician is here
Low refrigerant
As soon as he started adding , the water started pouring from the drain
So ... one of two:

1: in the past six weeks I lost 4.5lbs of refrigerant through a big leak that wasn't there before
2: previous tech (six weeks ago) didn't check the freon and the 2 lbs were lost slowly during the past few years since the last check

Hmmmm .... I wonder which is it?

>>1026720
at 2: I meant 4.5 lbs
at first he charged it with 2 then checked something else then charged it with another 2.5 while I was writing this

time to make some angry calls, "good news" is that the company is registered with BBB

>>1026722
HVAC tech here.
the previous technician is either retarded, purposely or accidentally let out some refrigerant, or you have a new, large leak.
4.5 lbs for that sized system is a large amount - you would have noticed it struggling to maintain temperature long before it froze if it was a slow leak.
I would give it a couple days and see if it freezes again. personally, every time I add refrigerant to a system with no identified leak, I like to schedule a free follow up visit for a couple weeks later just to quickly recheck the pressures.
probably not any sort of "sabotage" to your equipment, maybe just laziness and incompetence, but the amount of refrigerant added is concerning. sometimes shit happens. even doing your job well, after touching 1000+ units a year a couple are bound to break down shortly after you leave, even if they really were in good shape at the time.
keep an eye on it, if everything looks good in a couple weeks was most likely a sloppy technician, otherwise I'd call company #2 for the repair.

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>>1026754
the first tech spent LITERALLY a few seconds with the gauges in his hand
100% my fault for not watching him at that moment
right now the air coming out of the vents is colder than it ever was (I bought the house 13 months ago so I spent two separate summers in it)
SUBJECTIVELY I can say that for the past year the system wasn't that cold BUT

the house is relatively well insulated with thick insulation in the attic and attic fans and the sidings are (almost) white
there's some vegetation in front of most southern/eastern facing windows
There are only 2 rooms with eastern facing windows that have no shade
there's a forest that provides shade starting around 2-3 PM for the whole house

all this explaining why it wasn't that obvious

Anyway, I should be good at least this summer, probably a month from now the temperatures will start to go down

Thanks everyone for all the suggestions!